Alonefire X40

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Alonefire X40 Review: Thrower Flashlight

Alonefire X40 specifications

Brand/modelAlonefire X40
Beam intensity1Mcd / 2000m (exaggeration)
Battery config.1*21700
Review dateNovember 2021


A budget light claiming 2km of throw, with vague specs, from a something-fire brand? Just the kind of flashlight that piques my interest!

Digging into the X40 product specs, there’s mention of a “white laser” and a “blue laser that excites the yellow fluorescent material”. Oh, Is this actually a budget LEP like the Richfire LEP one I reviewed? I’ll save you the suspense: no. Alonefire seems to have copied some text from an LEP flashlight when listing the X40.

The X40 is actually a fairly standard Osram “NM1” flashlight, though uses an unusual optic. More on this later.

I don’t know much about Alonefire. Looking through their catalog, they seem to sell Shadowhawk X800 clones, SK68 clones and some UV lights and all sorts of other zoomies. Uh oh…

So, we know it’s not an LEP, and because it has similar dimensions to the Convoy L21A and Acebeam L19 we can’t expect it to meet its 2000m throw claim. But we have got a very throwy LED and a wide bezel. Let’s find out what it’s really like.

Package quality.

My last review was an Olight, with packaging that had every attention to detail. The X40 is the exact opposite. The cardboard parcel the light was shipped in was the only box: no product box inside, no logos, nothing. Still, the light was protected by sufficient plastic foam and arrived safely. Similar to a Convoy flashlight, as long as the light gets to you then the manufacturer is happy.

In the box you get:

  • Alonefire X40 flashlight
  • Alonefire 21700 cell (flat top, 4000mAh)
  • Yellow filter lens
  • USB charger
  • Lanyard
  • Micro USB cable
  • Spare O-ring
  • Cigar grip ring

There’s no manual, warranty, or any paperwork at all.

Flashlight in use

When you pick up the X40, the first thing you’ll notice is the big head and fairly slim body tube, thanks to the 21700 cell. It’s actually noticeably smaller than the Astrolux FT03 and when holding it and it’s most similar to my Convoy Z1. This means it won’t really fit in a trouser pocket without sticking out substantially. It should fit in a jacket pocket easily enough though.

It’s easy to grip, thanks to the knurling and heat fins. The knurling actually feels a bit sharp and is uncomfortable to grip. It’s balanced OK, despite the overly large head.

Alonefire has used a dual switch with the X40: A forward-clicky physical tail switch to turn on/off and a side e-switch to change modes. The tail switch sits in a U-shape recess (AKA saddle shape, or what I like to call Pringle shape), protecting the switch but allowing your thumb to access it. This also allows the light to tail stand on a flat surface and includes 2 holes for the lanyard.

The e-switch is easy to find in the dark and whilst it feels thin, it still makes a satisfying click. Aside from the e-switch, the head is even all round, so there’s no anti-roll feature.

The package came with a cigar grip ring that attaches onto the body tube. This works very well with the forward-clicky switch, though highlights the knurling quality being on the low end.

Build Quality, and Warranty

I’ve mentioned the knurling being uncomfortable to grip but aside from that the outside of the light appears to be good quality.

The anodisation on the aluminium is slightly shiny and I don’t see any faults in it. The heat fins are sufficiently deep and have a bevel so they’re not sharp. The bezel looks to be stainless steel.

Opening up the light… squeak! There’s no lube at all on the threads. I’d recommend adding some to help with waterproofing and so you can change the battery without the light making squeaking and scratching noises. The square cut threads themselves look to be cut well and are anodised on both ends of the body tube. There’s a white o-ring at each end too.

The bezel and lens came out easily enough but I couldn’t remove anything further without risking damaging it. The driver’s retaining ring doesn’t seem to want to move either.

Warranty: 7 days to return if any quality problems, 1 year warranty.

LED, Lens, Bezel, and Reflector

So, have you guessed what’s under the glass lens? LEP? Nope. Reflector? Nope. TIR? Getting closer… Aspheric? Almost… Fresnel lens? Yes!

Removing the protective glass lens you can see that Alonefire has put a 60mm Fresnel lens in this light. This is plastic (perhaps acrylic) and performs a similar function to an aspheric lens. 

So why not go with an aspheric lens? From what I can tell the main advantages of a Fresnel lens is the price. They’re also much lighter than glass aspheric lenses. Both these benefits are much more significant in larger flashlights.

The downside to them is the inefficiency due to imperfections where the bumps are. This means the Alonefire X40 should perform almost as well as a similarly sized aspheric light. The other issue with Fresnel lenses is the chromatic aberration, meaning the lens is like a prism that splits the light into a rainbow. The light is still mostly white but it’s not going to win any awards for Flashlight With Best Quality Beam.

The light also comes with a yellow filter lens. This one seems to be made of plastic instead of glass. This would be a bit awkward to replace outdoors at night as you have to unscrew the bezel.

On to the LED then. Alonefire calls this an “NM1” LED. I can’t get access to it but from the proportions, I can tell it’s an Osram CSLNM1.TG, also known as the W1. This is the same tiny LED that’s used in lights like the Lumintop GT Nano and is well known for its throw.

The W1 is a cool white LED and can be driven up to around 900 lm in some flashlights.

Measuring the light on low with the Opple Light Master 3 for some rough numbers, I get:

  • CCT: 6342 (cool white)
  • CRI (Ra): 66.0
  • Duv: 0.0052

To show how much the light is distorted, at the edge of the hotspot I get a CCT of 2684 (warm white).
This all results in a long distance beam with virtually no spill at all. It’s not an LEP but you might be mistaken if you just saw the beam. In fact, the beam is more LEP-like than the Richfire LEP I previously reviewed.

Dimensions and size comparison

  • Length: 15.02cm / 5.91 inches
  • Head diameter: 6.34cm / 2.49 inches
  • Body diameter: 2.60cm / 1.02 inches


  • Without cells: 227g / 8.0oz
  • With cells: 297g / 10.5oz

Throw flashlight comparison

Compared to other popular long-range flashlights.

From left to right: 

Driver & User Interface:

The user interface is very straight forward, thanks to having 2 separate switches, one for power and 1 to change modes. The tail switch being a forward clicky, works well with this too, as you can turn the light on just for a moment.

Available modes: Low, Medium, High, Strobe

Tail switch from off:

  • Click: on
  • Half press: momentary on

Tail switch from on:

  • Click: off

Side switch from on:

  • Click: change modes (low, medium, high)
  • Double click: strobe

Mode memory:

  • Yes

Low voltage warning:

  • Yes. The light turned off with the cell at 3.18V


  • Strobe

Lock-out mode: 

  • None (aside from unscrewing the tail cap ¼ turn)


  • None detected

Batteries & Charging

The Alonefire X40 comes with a 21700 cell and an Alonefire branded cell charger.

Alonefire provided their own wrapped flat top 21700 cell in the package, which is a nice surprise (I should have read the product listing better). The wrap says 4000mAh, which roughly matches up with the 4176mAh my charger put in the cell. The cell is 71.0 mm long.

Thanks to the springs on each end, the X40 should take any flat or button top cell as long as it’s not too long. A 75.6mm cell with a charging circuit didn’t fit. You could use longer 18650 cells if you wanted – a 67.6mm long 18650 worked fine, though could do with a spacer to stop it rattling.

The USB charger that Alonefire provides is fairly basic but does the job fine. It’s micro USB and can supposedly draw up to 2A, though I could only get it to take just over 1A. It actually seems to take cells up to about 76mm. When charging there’s a blue indicator light, which turns green when the cell is charged up to 4.15V.


Lumen measurements:

Lux meter: All lux and lumen measurements are from my home made integrating sphere, calibrated with a S2+ measured by Maukka. Measurements are done with a UNI-T UT383S lux meter and Adafruit TSL2591 connected to a Raspberry Pi (using RuTiTe by bmengineer). Expect them to be within +/-10%.

DMM: Current readings were taken with a Precision Gold PG10B DMM for low currents and a Mustool X1 clamp meter for high currents.

I used Alonefire’s provided cell, charged to 4.15V each time.

Mode Amps at startSpecs@ start@30 sec@10min

429 lumens out the front isn’t much. That works out to around 20 to 30 lumens per Watt, which is terrible efficiency for brightness. But remember that this light is all about the throw – with a reflector this light might have a much higher lumen output but most of that gain would be from the spill.

Parasitic drain:

  • None

Runtime graph

On high the X40 starts off at 411 lumens, jumps up a little and then drops to about 300 lumens after 10 minutes. From here it lasts 1h20m before dropping quickly whilst flashing, then turning off.

On medium the X40 starts off at 236 lumens and remains steady, only dropping to xxx at 2h15m before turning off.

Throw numbers: 

Throw was measured indoors at 10m with a UNI-T UT383S lux meter.

Of course, it doesn’t hit the claimed 2000m but it’s still a respectable 386kcd or 1242m throw. Fairly close to the Astrolux EA02.

Medium still hits 230kcd, which is close to 1km throw. The 300 or so lumens that high can sustain works out to about 288kcd (1074m).

ModeSpecsCandela measuredMetersYards
High2000m385,717 cd1242 meters1358


The distance to the building is 170m. Photos were taken with a Pixel 3a, set to 1/3s shutter speed and ISO 400, F1.8. 

Disclaimer: This flashlight was sent to me for review at no cost by Banggood. I have not been paid to review, nor have I been holding back on problems or defects.

Final Verdict


  1. Lots of throw in a small package
  2. Zero spill beam that looks like a LEP!
  3. Comes with cell and charger


  1. Way below specs (as expected)
  2. Threads and knurling are sub par
  3. Ugly beam

Explanation on star ratings:

1: Avoid: my phone flashlight would be a better choice – 2: Poor: significant defect or issues; almost unusable – 3: Average: some defects or issues; but still usable 4: Good: recommended (minor issues) – 5: Great: highly recommended

Reviewer Dave
Author: Dave

4 stars: ★★★★

A light that looks like a LEP, hits 386kcd, throws 1km for over an hour, and costs around $70! Just like a LEP, lumen output is low but the sustained candela is impressive.

Before seeing this I thought the beam of my Convoy Z1 was a close alternative to a LEP (aspheric optic with W2 LED, around 225kcd). The Alonefire X40 puts the Z1 to shame and could easily be mistaken for a LEP.

The measured candela is in the same ballpark as the Convoy L21A with the same LED and isn’t far off the bigger Noctigon K1 or Acebeam L19. None of these have the same beam though – even the Acebeam L19 with TIR optic has more than just a hotspot. If you want a virtually zero-spill beam then you either pay much more for a LEP or find a light with an aspheric or Fresnel lens like the Alonefire X40.

Of course, it’s not perfect. It seems robust enough but the build quality is definitely towards the budget end. Advertising it as a LEP that hits 2km is dishonest too, though at least they didn’t claim 999,990 lumens.

I’m giving the X40 4 stars as despite its faults it’s still a great flashlight if you have a need for a light with no spill, whether that’s for lighting up long tunnels, highlighting specific objects or just taking beamshots for upvotes on Reddit.
Summary: Want to have a LEP flashlight but don’t have the budget for it? Get the Alonefire X40 and join the zero-spill club for a fraction of the price!

Alonefire X40 for sale

The Alonefire X40 is not for sale any longer. Have a look at some of the best long-range flashlights we reviewed.

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.