Review: Olight M20SX Javelot (18650 or 2x CR123)


Flashlight Enthusiast
May 5, 2010
Hove, UK
Author's Statement for Transparency and Disclosure
The test sample/s featured in this article have been provided for technical testing and review by the manufacturer. Test samples are retained by the reviewer following publication of the completed review for the purposes of long term testing and product comparisons.

All output figures and test results published in this review are the sole work of the reviewer, and are carried out independently and without bias. Test results are reported as found, with no embellishments or alteration. Though best endeavours are made to maintain the accuracy of test equipment, the accuracy of these results is not guaranteed and is subject to the test equipment functioning correctly.

Part of the Olight Javelot range, with its customised XM-L2 LED, the M20SX gives you much more throw than you would expect from a 2xCR123/18650 light with a compact sized head.


Taking a more detailed look:

Giving the M20SX that more important feel, it arrives in a hard case instead of a cardboard box.


The case contents are well presented.


The kit includes the M20SX, an interesting holster, frosted glass beam diffuser, CR123 holder, a lanyard, two CR123 cells, two spare o-rings, spare GITD switch boot and the instructions.


When in the holster, the tail-cap of the M20SX protrudes from the holster. What can’t be seen here is that there is a hole in the base of the holster which means you can use the M20SX while still in its holster.


The belt loop has a velcro closure, plus a D-loop.


A very nice feature of the M20SX’s holster are the spare cell holder on each side. These work very well for 18650 with no concern over security, CR123s do work as well, but could fall out if the holster is shaken around.


The tailcap has the same grip pattern as the body and here you can see the blue mode switch on the side and the black main tail-cap switch.


The bezel is a great mix of reasonably aggressive shaping but no sharp edges to cut the holster or pocket. As the bezel does not hold the lens in place, it can be unscrewed and left off if you prefer not to use it.


And the custom de-domed XM-L2 LED. Unlike many de-domed LEDs, the M20SX’s LED has a coating a bit like a super-low-profile dome to help with the emitting efficiency.


The custom XM-L2 LED sits in a smooth reflector.


With the M20SX being a Javelot model, it is aimed at beam range. To make the light more useful, Olight include an excellent frosted glass diffuser in a rubber mount that fits over the bezel. With this you get two beam profiles in one.


Though there is a gold plated ring terminal for the battery tube connection, the threads in the head are bare so the M20SX will function even if the head is not fully tightened. The positive contact is a spring.


The battery tube removed with the bare head end threads and anodised tail-cap threads.


The head end threads are well lubed and square cut.


The tail-cap end threads are also square cut, but are anodised.


Inside the tail-cap the negative terminal is a sprung post and a cover plate surrounds this with two holes in it. These holes can be lined up to expose the underlying holes in the tail-cap retaining plate, allowing you to unscrew it.


As I wanted to fit the GITD switch boot supplied with the M20SX, I disassembled the tail-cap to allow me to fit it.


The glow is a blueish-green.


The M20SX with GITD switch boot fitted.


To get an idea of size, here is the M20SX next to its two possible power sources, 18650 or 2xCR123.


And next to the M2X-UT with its much larger head.


The beam

Please be careful not to judge tint based on images you see on a computer screen. Unless properly calibrated, the screen itself will change the perceived tint.
The indoor beamshot is intended to give an idea of the beam shape/quality rather than tint. All beamshots are taken using daylight white balance. The woodwork (stairs and skirting) are painted Farrow & Ball "Off-White", and the walls are a light sandy colour called 'String' again by Farrow & Ball. I don't actually have a 'white wall' in the house to use for this, and the wife won't have one!

As it comes, the beam of the M20SX is not ideal for indoor use. Here you can see the tight bright hotspot. The beam does have a strong warm tint.


Fitting the included diffuser transforms the beam for indoor use giving a lovely diffused beam.


Though the spill is OK, the M20SX’s strength is throw with its penetrating hotspot.


Modes and User Interface:

The M20SX is relatively simple with three steady modes (High, Medium, Low) plus strobe.

The tailcap has both a forward clicky main switch and a second switch on the side for mode selection.

In general operation, half pressing or fully clicking the tail-cap switch turns the M20SX onto the selected steady output mode. Once ON, pressing the side switch cycles through Low -> Medium -> High -> Low etc.

From OFF the M20SX has quick/direct access to both High and Strobe.

To get to High from OFF, use a double-tap of the tail-cap. Keeping it half pressed allows you to release it for momentary operation or clicking it on keeps the output on High (like this the mode switch does nothing if pressed). After switching the M20SX OFF, a single press of the tail-cap returns to the steady output level set by the side switch.

To get to Strobe from OFF, use a triple-tap of the tail-cap. Keeping it half pressed allows you to release it for momentary operation or clicking it on keeps the output on Strobe (like this the mode switch does nothing if pressed). After switching the M20SX OFF, a single press of the tail-cap returns to the steady output level set by the side switch.

To get to Strobe from OFF, you can also just press the side switch. This does not allow for latching the output on and only works as momentary operation.

Due to the double and triple taps of the tail-cap giving High and Strobe output, to use the tail switch for momentary operation the frequency of pressing the switch must be relatively low. A ‘feature’ was found that by gradually increasing the frequency of switch operation, the M20SX would go OFF even with the switch fully pressed. Switching OFF and On again instantly fixes this.

Batteries and output:

The M20SX runs on either 18650 or 2x CR123 for highest output you need to use CR123.

To measure actual output, I built an integrating sphere. See here for more detail. The sensor registers visible light only (so Infra-Red and Ultra-Violet will not be measured).

Please note, all quoted lumen figures are from a DIY integrating sphere, and according to ANSI standards. Although every effort is made to give as accurate a result as possible, they should be taken as an estimate only. The results can be used to compare outputs in this review and others I have published.

Olight M20SX using Olight CR123 cellsI.S. measured ANSI output LumensPWM frequency or Strobe frequency (Hz)
High (18650)6231170
Diffuser loss-28.4%

* Beacon and Strobe output measurements are only estimates as the brief flashes make it difficult to capture the actual output value.

Peak Beam intensity measured 32922lx @1m giving a beam range of 363m.

There is parasitic drain, but it is very low at only 1uA. This means it would take 296 years to drain even a lower capacity 2600mAh 18650.

PWM is used, but at 1170Hz is not noticeable in use, even though I’m very sensitive to PWM.

In the runtime trace, you can see the different runtime profiles on CR123 and 18650. CR123 gives better performance for up to an hour of use on high. After 1 hour, 18650 stays ahead.


Taking a closer look at the start of the trace you can see more clearly the programmed drop in output after 3 minutes down to about 400lm for the CR123s



This is a new section I am adding to mention any minor niggles I came across during testing, in case the information helps anyone else.

When trying to find the speed at which the M20SX changed from momentary operation of the memorised mode, to direct access to High, when gradually increasing the frequency of switch operation, at a certain frequency the M20SX would have no output even with the switch fully pressed. This appears to happen when getting close to the timing where momentary stops. Switching OFF and On again instantly fixes this.

As per the description of this section, this information is provided in case anyone else finds a similar 'issue' that might be fixed in the same way.

The M20SX in use

As with many single 18650 / 2x CR123 lights, the M20SX is a great mix of size and performance. It handles like a typical light in this category.

The mode switch is relatively easy to get to, but can prove illusive, especially if wearing gloves, however, what works really well is the way Olight included access to High and Strobe using double and triple-taps of the main tail-cap switch. Like this, you can set the M20SX to low, and know that if you want high, use a double-tap, if you want Strobe, a triple-tap.

The warm tint of the LED can make the output appear less strong than a cool-white beam would, particularly when looking at throw. This is typical of warmer tints, even when output power is the same, so is nothing to worry about, in fact in misty conditions you do seem to be able to see further as you get less glare.

With only a relatively compact size head, the M20SX manages great throw. For looking into enclosed spaces, inspecting engines, searching through storage etc this is great. Even better is that Olight include a diffuser turning the M20SX into an excellent flood light for soft lighting when working a short distances.

With its space cell holders, the M20SX in its holster can be a little bulky, but from my own perspective I’d much rather the utility of the spare cells than a smaller holster.

On the subject of the holster, with the exposed tail-cap and hole in the bottom to let the light out, you can get ground lighting, simply by switching the M20SX on when it is in its holster on your belt. Hands-free lighting where you need it to see where you are walking in the dark.

Though no single feature is outstanding (there are stronger throwers, brighter 18650 lights, more compact EDC lights etc), the M20SX puts in a strong performance across all aspects in this 2x CR123/1x 18650 category. Good throw or diffused flood, easy access to various modes and a well thought out holster with spare cell carry and hands-free function, all go to make this a very useful light.

Review Summary

Things I likeWhat doesn't work so well for me
700lm on CR12318650 performance a little lacking
Strong throw in this class of lightBeam tint noticeably warm
Direct access to High and Strobe with main switchMode switch can easily be missed
Holster with spare cell holders and hand-free function
Diffuser included
32922cd / 363m beam range
Removable strike bezel


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Last edited:


Flashlight Enthusiast
Feb 9, 2015
Thanks for the review.
damn shame regulation is not better.
hope it will be improved and upgraded with the xpl hi in the future

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