Fireflies E07x Pro Review – It’s Complicated

“It ain’t the Fireflies, but the quality control that’s negligible.” – u/ciaran144

The Boring Stuff

I purchased this light from the official product page and paid $78. Since I ordered, the price appears to have increased to $98! More on that in the competition section. I chose the free shipping and it took exactly one month to arrive, but the tracking link did not work until it arrived in the US near the end of the journey, and they didn’t actually ship the light until I emailed them about it a week after I ordered. If you have the opportunity to buy from a reputable reseller instead of Fireflies directly, I would go that route. Below are the official specs.

Presumably the 7000 lumen output figure is only going to be true for low CRI, cool white emitter options like XPL-HI’s and high color temp SST20’s. Other options (like the SST20 4000K’s I chose) will be lower.

The body tube of the light may appear damaged in some of these photos. Read on for why that is.

What comes in the box?

Fireflies did an excellent job with the packaging. The light comes in a high quality black box with fireflies branding and a magnetic front closure. Filling the box is a high quality cutout of open cell foam to protect the light and keep it in place. Also included are a manual, a nice 18650 adapter, three spare o-rings, an aluminum spacer, and a really low quality lanyard.

The 18650 adapter is high quality and appears to be machined plastic with a brass button on one end. The spacer is just a machined aluminum disc with a button on it. The three o-rings are nice (you might need them). These are all smart inclusions. The lanyard is really sad though and does not fit the same high quality level that’s present everywhere else. There’s not even any good spot on the light to attach it.

Size & Measurements

From left to right:
Fireflies E07x Pro
Convoy S12
Convoy M1 with Thyrm Switchback
Emisar D4V2
Noctigon KR1

MeasurementMeasured (mm)
Head/Bezel Diameter38.5
Bezel Depth10.2
Switch Diameter11.6
Switch Proudness2
Tailcap Diameter (maximum)29.6
Tailcap Diameter (minimum)27.5
Tailcap Groove Width2.6
Body Tube Diameter (minimum)25.5
Body Tube Diameter (maximum)30.3
Body Tube Diameter (internal)22.1
Pocket Clip Thickness0.75
Pocket Clip Ring Diameter (inside)27.4
Pocket Clip Ring Diameter (inside, minimum that will fit)25.5
Pocket Clip Ring Diameter (outside)29.6
Ride Height (sticking out of pocket)23.3
Optic Diameter35.8
Lens Diameter35.8
Lens Thickness1.5
Magnet Thickness20.0
Magnet Diameter5.0
USB Port Width10.5
USB Port Depth3
USB Port Height6.4
Cooling Fin Thickness3.5
Cooling Fin Width (between them)3

User Interface

E07x comes loaded with Anduril 2, the best flashlight user interface available at the time of writing. It’s easy to use for basic operation, but allows a myriad of customization options and extra features. It’s continually being improved too, and I’m thrilled that it’s included here. It’s far too complex to do a whole UI breakdown, but here are some of my favorite features:

  • Simple basic operation (1 click on/off and hold to change brightness)
  • Shortcut to moonlight
  • Momentary turbo
  • Customizable mode memory
  • Customizable minimum & maximum brightness
  • Customizable smooth or stepped brightness adjustment
  • Battery voltage readout
  • Sunset timer (dims the light over a customizable period of time)

Ultimately, my absolute favorite feature is that Anduril 2 defaults to a limited “simple UI” which is no more complicated to use than any other typical e-switch UI you’ll find on lights from Olight, Thrunite, etc. This eliminates the old argument against Anduril 1, that “it’s too complicated”, and means you can buy an Anduril 2 light for the average consumer and they won’t get stuck in some weird mode.

Modes, Brightness & Throw

Disclaimer & Update: Since writing this review I’ve measured Turbo at 3200 lumens, only about 2/3 of my initial 5000 lumen guess. Keep that in mind when reading the lumen numbers below that I haven’t had time to update yet.

I like my lights set up with 5 modes: moonlight, low, medium, high, and turbo. In the case of the E07x, I accomplished that by using the stepped ramp with bottom of ramp set to level 1, top of ramp set to level 149, and 4 steps in-between. Normally I do 1-150 with 5 steps, but 149 and 150 are so far apart that this setup works best for this light. It also gives me a shortcut from off to high in addition to turbo, which is nice.

LevelLumens (Estimated) Candela Throw (meters)
150 (Turbo)5000 27,000329
149 (High)2040 11,000210
100 (Medium)780 4,200130
50 (Low)140 77055
1 (Moonlight)1 65


E07x has two driver channels, a FET Turbo-only channel, and a 6A Buck channel. The FET channel is not super well regulated, as you would expect, but it can still do more than 1000 lumens with a mostly discharged battery. All the modes within the buck channel are delightfully well regulated. You get full output even with a low battery on all of them except high, where I suspect the current draw causes too much voltage sag with a low battery and that’s why the brightness is lower. I’m delighted to see such a high output light with such great regulation on most of the modes.

Runtime & Currents

Turbo (150): Turbo starts out at an estimated 5000 lumens. It stays there for a little bit past 30 seconds (enough to meet ANSI standard) and then drops down to about 1600 lumens over a couple steps. Over the next 15 minutes or so it slowly drops down to a comfortable 900 lumens where it stays until just before the two hour mark. By two hours, low voltage warning/stepdown has kicked in and the light settles down to moonlight mode over several steps. Moonlight lasts another two and a half hours, with the light finally turning completely off at four and a half hours.

High (149, top of regulation): High looks almost identical to Turbo. The only differences are that the highest output lasts for a good four minutes before stepping down, moonlight lasts a little longer on this mode than it did on turbo before low voltage protection shuts the light off, and the stabilized brightness isn’t perfectly flat.

Medium (100): Medium is just under the max sustainable brightness level with these emitters. There’s no thermal stepdown so it provides a perfectly flat ~800 lumens for a little over two and a half hours before the low voltage stepdown kicks in.

Low (50): Low is a perfectly flat 140 lumens for a whopping 16 hours before low voltage stepdowns kick in. As on all the runtime tests I did, moonlight lasts for several more hours after the big low voltage stepdowns.

Bonus Runtime: When using sunset mode, I noticed that the dimming wasn’t perfectly smooth. Sometimes it seemed like it would be constant for awhile and then I would step down pretty dramatically over a few steps. It’s not distracting or anything, it’s just something I noticed when I was watching it. I tested it and here’s what I found.

LVP: E07x Pro does have low voltage protection. It kicked in on every runtime test I performed unless I ended the test early.

Current: Unfortunately, I had issues measuring current when the light was actually turned on so I was only able to measure standby currents. For these measurements the aux LED’s were set to constant on red.

Level Current @ Tailcap (milliamps)Estimated runtime (with Molicel P42A)
Parasitic Drain (aux high) 1.9888 days
Parasitic Drain (aux low)0.0667.3 years
Parasitic Drain (aux off)0.03912.3 years

Emitter & Beam

There is a wide selection of emitters for the E07x.

I chose the SST20’s in the FA4 bin. They are 95CRI, 4000K, and a little bit on the rosy side. They’re perfect. They sit behind a beautiful Ledil Anna optic and a glass lens.

I don’t think I could have hoped for a better beam profile. It’s floody as expected, but with the SST20’s and the narrow optics fireflies chose, it’s not too floody. It’s got just enough reach to be impressive but is also pleasant to use up close. This beam is exactly what I wanted and I think it’s perfect.

E07x Pro SST20
E07x Pro SST20

One thing I was concerned about when ordering was starbursting. My Emisar D4V2 with SST20’s displays some pretty bad starbursting around the corona. It’s not very noticeable outdoors, but if I’m walking through my home at night it’s noticeable and a little bothersome. I’m happy to report that this is not an issue with E07x. There are some minor artifacts near the very edges of the beam, but none as bright or as close to the center as the starbursting from my D4V2. In daily use the beam is nice and even. It’s just a little bit tighter than my D4V2 also, which is perfect for me.

Moonlight & Tint Comparison from left to right:
Skilhunt H04 | RC LH351D 4000K
Sofirn SC21 | LH351D 5000K
Fireflies E07x Pro | SST20 4000K | FA4 Bin
Emisar D4V2 | FET+1 Driver | SST20 4000K | FA3 bin I think
Convoy M1 | H17Fx Driver | SST20 4000K | FB4 bin

Moonlight mode on E07x is satisfactory. It’s not amazingly dim but it’s not too bright either. My guess is it’s right around 1 lumen. This shows off how rosy these emitters are too! There’s some very slight flickering on moonlight mode (and only moonlight mode) but it took me a month and a half of daily use to notice so it’s not a big deal at all.

E07x not only comes with the main 7 emitters, but also 6 RGB auxiliary emitters that sit behind the optic. It might have been cool for there to be a few more (the Emisar D4SV2 has sixteen) but they do the job. They’re dimmer than the Aux LED’s on my D4V2 and that’s a wonderful thing. I’ve always felt that the ones on my D4V2 were too bright in high mode and too dim in low mode. The LED’s on the E07x on high mode are the perfect brightness where they look great but aren’t distractingly bright. On low mode they’re so dim that they can be hard to see unless it’s pitch black so that’s a little bit too low. Anduril 2 also includes a new color mode for the LED’s, disco mode, and it looks really cool. I have noticed that one of the Aux LED’s on my sample is a little finicky and doesn’t always like to work. Below is a comparison between my D4V2, E07x, and the lowest moonlight of any light I have, the Thrunite Catapult Mini.

D4V2 High, E07x High, Catapult Mini Lowest Moonlight


Fireflies listened to the community and knocked it out of the park here. They used a Lume1 buck driver with a 6 amp fully regulated channel for maximum efficiency and an unregulated FET channel just for getting maximum output on turbo. The buck circuit takes the 4.2V or less of the battery and efficiently converts it down to the ~3V needed to drive the LED’s instead of wasting that extra voltage as heat.

I did notice a couple of odd things about the driver. The first is that it produces an audible ticking sound when you use either party strobe or tactical strobe. I’ve spoken to other Fireflies users and they’ve reported the same thing. It’s not a problem, just interesting. The other odd thing is that the ramp is not completely smooth all the way up. Levels 1 to 149 are smooth and visually linear, but then there’s a huge brightness jump from level 149 to level 150 (turbo). My assumption is that levels 1-149 are all within the regulated 6A channel and level 150 is the full direct drive channel. Again not an issue, just something interesting.

It’s worth noting that Fireflies included flashing pins on the show side of the driver and they are in Emisar/Noctigon’s layout. I’ve verified I can connect to the MCU using my Emisar/Noctigon adapter, but no new firmware versions exist for E07x. Toykeeper wasn’t involved in this light’s creation so it doesn’t get regular firmware updates through her repository, which is unfortunate.

Design & Construction

Build quality & design here are excellent with a couple of exceptions. I think E07x is a fairly attractive light, especially with the stainless bezel and clip and stainless-looking button. The anodizing is a matte and high quality. There’s something about it that I can’t describe, but it just feels high quality in a way that most other lights don’t. It feels even a little nicer than my Emisar/Noctigon lights. The only one I have of comparable feel is Acebeam E70.

It’s worth noting that there is no water resistance rating listed for this light. I have a couple of buddies with Fireflies NOV-mu’s that have experienced water ingress in those lights despite their IP-66 water resistance rating (which is low). E07x has all the right o-rings in all the right places but I am not willing to potentially sacrifice mine to test it. I don’t think water ingress should be an issue unless you do something stupid like take it swimming

The O-ring on the head-end of the body tube isn’t captured particularly well. It has a tendency to get pushed out when tightening down the head after a cell swap. This got progressively worse the more I used the light, so perhaps the grease was wearing off or something. Now I try not to swap cells unless I absolutely have to. Fortunately, there’s integrated charging. I found that the best solution to getting a herniated o-ring back in was to loosen the head, then tighten a bit and loosen a little bit less, sort of like two steps forward one step back. If I do that a lot as I’m tightening it usually goes smoothly. I re-applied some lubricant to the inside of the head where it contacts the o-ring and that helped as well. Fortunately, if it ends up tearing it, they include three replacements in the box. In the photo below you can see a herniated o-ring (and also how much the cooling fins like lint & dust).

The spring in the tailcap is easily removable with some pliers and you can remove the magnet if you want to once the spring is out. The spring will rattle around a fair bit if there’s no battery inserted, but with a battery the light doesn’t make a peep when shaken.

The threads on the head end of the body tube are fine, triangular cut, and well lubed. They can be a little hard to get started and it’s fairly easy to cross thread if you’re not careful. Seeing as this is the best way to do a cell swap, these threads should be thicker and square cut. They are nicely anodized though so mechanical lockout works great by loosening the head slightly. The tail threads on my second body tube and tailcap are un-anodized, square cut, well lubricated, and not especially smooth, but not too bad.

I think the un-anodized threads on the tail are a good design because they allow for some variety in the pocket clip thickness. That means if you find another captured clip like this that you can fit around the threads, it will work. u/Ariett59 on Reddit uses slightly modified Noctigon KR4 clips on his Fireflies lights.

The tail threads on my first body tube & tailcap are the worst threads I have ever seen. They are completely un-anodized and un-lubed. When I got the light out of the box, they were unbelievably rough and gritty. I tried to remove the tailcap a second time to clean and lube the threads and the tailcap seized halfway. It would not loosen or tighten anymore. I ended up having to use pliers on both the body tube and tailcap to get them separated. Once I did, this was the aftermath.

Thankfully, with the help of a file and a dremel, I was able to remove the damaged threads and wrench the tailcap back on with pliers again. They will never come apart again. I don’t believe this is representative of every fireflies light, but I’ve heard of two other users having the exact same issue. Fortunately, most users report perfectly acceptable tail threads, but the risk is something you need to be aware of before ordering.

I contacted fireflies about it and they promised to send a new body tube and tailcap, then I heard nothing for six weeks. I finally managed to get a reply by sending an email to their alternate email address from my alternate email address and they shipped out the new parts. They took about three weeks to arrive, and once again the tracking didn’t work at all until they got to the US.

Now, three months after I placed my order, I have a complete and fully functional light.


The switch on E07x is a large, proud, metallic, indicating, electronic, side switch. I can’t tell for sure whether it’s actually metal, but it’s very shiny. It’s easy to find and use since it’s so large and proud. It feels nothing like the charging port on the opposite side of the head. It’s got an audible click but it’s on the quieter side and it’s tactile enough. It works well and it doesn’t make complicated strings of clicks and holds difficult like some switches do.

The center of the switch is translucent and glows when charging. That’s the only time it glows though. More on that in the batteries & charging section. In the next version I think it would be cool for the switch backlight to match the aux LED’s except when the light is plugged in.

I have one problem with the switch but it’s a significant one: accidental activation. This light is a hotrod and it can definitely burn a hole in your pockets if you’re not careful. I find that the light turns on in my pocket every time I get out of my car. That’s the only time it turns on, but it happens every time. I’ve just made a habit of checking my light when I get out of the car and it hasn’t caused any problems. I also set my top of ramp to level 149, which is significantly dimmer than turbo, and I did some testing to make sure it won’t burn my particular pockets.

Fortunately, Anduril 2’s lockout mode allows momentary use of the bottom of the main ramp as well as the bottom of the secondary ramp or manually memorized mode, so if you do need to carry it locked out it won’t be completely useless. I suspect it will be too big for many users to want to carry anyway. You can also set auto-lockout just in case you forget to lock out the light before putting it back in your pocket.

Toykeeper has introduced an update to Anduril 2 that adds a few minor features, including one that allows you to disable ramping past moonlight from off. If you disable that and the switch gets held down in your pocket it will only turn onto moonlight and won’t continue ramping up from there. What a great feature! Mine has an older version of the firmware without this feature, but it’s possible that yours will come with the updated features.

Carry & Ergonomics

Ergonomically the E07x is perfect. I’ve got large hands and it fits them like a glove. The handle is just the right length. The switch is in just the right spot. It’s just the right diameter. The clip fits right in the bends of my fingers. It’s perfect. That’s all in a normal forward grip with my thumb on the switch, but a grip where my index finger is on the switch is also plenty comfortable to use. I can also use it in a reverse grip simply by squeezing the light in my hand, because the button is so accessible!

It’s a little bulky in pocket but not too bad. I’ve carried it every single day for two months and I intend for it to be my primary EDC light for the foreseeable future. It’s kicked my beloved D4V2 out of my pocket for the better beam, higher capacity, higher sustained brightness, improved UI, and those awesome ergonomics. I do think a deeper carry clip would have been nice and I wish the clip landed on a little bit softer spot.

The included lanyard is garbage and there’s no good place to attach it. The magnet in the tailcap is pretty excellent though. It’s super strong, plenty strong enough to hold up this heavy light horizontally on a vertical surface. You can even remove it if you want, which is a nice touch and I’m sure machinists will appreciate that.

Batteries & Charging

E07x can use three different kinds of batteries. It’s designed for unprotected flat top 21700 cells with a discharge rate in excess of 6 amps (for it to work) and in excess of 20 amps (if you want maximum output) and that’s what I recommend using. I used a Molicel P42A for all my testing unless otherwise specified.

Fireflies includes an 18650 adapter in the box, so you can also use any unprotected flat top 18650 as well. I tested with a Samsung 30Q and it worked fine. They also include a little aluminum spacer to replace the tailcap spring and magnet if you want to use a “2177C” battery, which I gather is a protected button top 21700 cell with a charging port built in. I tried to test this, but I couldn’t get the aluminum spacer to fit into the cutout for the magnet where it’s supposed to go. I probably could have forced it but I didn’t want to get it stuck.

The springs are pretty stiff and my sample slightly dented one of my P42A’s, which are a little bit shorter than most 21700 cells. I have seen other users report this as well and it’s a little bit disappointing. Fortunately it only dented my cell a little bit so it’s still perfectly functional. I believe the denting is a result of the spring bypass not allowing one or both of the springs to compress quite fully. It’s also possible they are just super stiff springs. Either way, Fireflies should simply make the body tube a millimeter or two longer to eliminate this issue and allow for a little bit wider battery variety.

For charging, E07x has a USB-C port built into the side of the head, opposite the button. C-to-C cables work just fine, but I have found that the opening of the port is a little small and not all of my cables fit. I put the dimensions of the opening in the size & measurements section. The light is fully functional when plugged in, but it freaks out and blinks a lot if you unscrew the battery tube so don’t plan on running it off USB without the battery connected.

The rubber flap covering the port leaves a bit to be desired. It’s not the worst I’ve seen, but it’s just a press fit and it’s come open by accident once during my testing. Ironically, it’s also a little hard to get open on purpose because the tab is too small to get a hold of. I think in the next generation of lights, it would be good for the port cover to be a little bit better protected, have a little bit larger opening tab, and have a lip around the underside to keep it in place better. If they simply copied Sofirn’s charging port covers I’d be happy. Charging a Molicel P42A from LVP cutoff took two and a half hours.

When plugged in, there are LED’s behind the switch that light up. If the light is charging, they light up red and blue. If charging is finished, they only light up red. However, if you look at the light from an off-angle you might only see red when the blue is lit up as well. This color choice technically works, but it’s not very communicative. A simple red while charging and green when fully charged would have been better. If you decide to fix this, Fireflies, just make the switch RGB backlit and match the aux LED settings while you’re at it.


Emisar D4V2: Shorter, narrower, cheaper, dimmer, mostly inferior drivers, more emitter options, optional backlit switch, more material options, smaller 18650 battery, no integrated charging, optional recessed switch, comes with Anduril 1 but can be reflashed with Anduril 2

Emisar DT8: The same as D4V2, but with a wide rectangular head about the same size as two D4V2 heads, and with 8 emitters instead of 4. Looks like a steampunk electric razor.

Emisar D4SV2: Shorter, stouter, cheaper, inferior driver, more emitter options, fewer emitters, fewer lumens, more throw, recessed switch, bigger 26650 battery, no pocket clip, comes with Anduril 1 but can be reflashed with Anduril 2, no integrated charging, many more aux LED’s

Zebralight SC700d: shorter, more expensive, little bit better driver, recessed switch, no integrated charging, better durability. good but inferior UI. I reviewed this one.

Astrolux MF01 Mini: same number of emitters, fewer emitter options (and no bin information), inferior driver, USB-C charging, 26650/21700/18650 compatibility, no magnet, non-RGB aux LED’s, better switch backlight, better protected switch, no pocket clip, older Anduril firmware, shorter and wider overall

Fireflies E07: No, not the E07x I’m reviewing here, the original E07. Fireflies has re-released it for 2021 with some minor updates. The big differences are that it’s a little smaller, a lot floodier, a lot cheaper ($60), uses a significantly inferior driver, and doesn’t have integrated charging.

About that E07… I mentioned in the beginning that the E07x’s price has increased from $78 to $98 since I bought mine. I think that and the release of the E07 are both a reaction to the worldwide chip shortage. Fireflies can’t get parts for their awesome Lume1 drivers so they are delaying the T1R and I suspect they increased the price of E07x to match the supply they have. I think they reintroduced E07 at a lower price with a much cheaper (and probably more accessible) driver so that they can continue selling lights despite the shortage. I think the delay of the PL47g3 and the introduction of the updated PL47g2 is related to this as well. I’m not happy about this arrangement at all, but I can’t really blame fireflies because they aren’t responsible for the shortage and they still need to sell lights.


It’s taken me a long time to write this conclusion. I adore E07x pro. It’s tied with the Convoy 4X18A SBT for my favorite light, despite all the issues I’ve had with it. It has kicked every other carriable light I have out of my pocket for the past six weeks since I got it. I want so badly to recommend it, but I can’t give it my full endorsement.

There’s almost nothing inherently wrong with it. The problem lies with the company, Fireflies. They have had quality control snafu after quality control snafu and they have notoriously bad email responsiveness. Plus they Jacked up the price (pun intended). If you get a bad one it’ll probably be quite a hassle to get it resolved. With that said, I would buy from them again in a heartbeat because E07x is that good. I’m chomping at the bit for the T1R to be released so I can give them more money.

Ultimately, whether I can recommend E07x depends on you. If you’re new to the flashlight hobby and looking to spend your hard-earned dollars on a great light, don’t buy from fireflies. The risk of getting a lemon is too high.

But, if you’re a seasoned flashlight veteran looking for the next great light to try out and add to your collection, buy it now. It’s just that good.

UPDATE: It’s come to my attention that you can buy E07x from Jackson Lee (JLHawaii808), a highly reputable enthusiast flashlight reseller based in the Hawaii. I fully endorse E07x provided that you buy from him because he provides the excellent customer service that Fireflies lacks. If you order, I would ask him to check the tailcap threads to make sure they’re lubed and acceptably smooth before shipping.

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