Olight M20SX Javelot Review

Posted by Best Light on

The M20SX Javelot is Olight's latest model succeeding the M20S-X which previously only had 550 lumens with an XM-L2 emitter. This newer model still uses that same XM-L2 emitter but it has been specially designed without a dome which has significantly improved throw. In addition to that, the max output has been increased to 820 lumens which is much closer to what a light of this caliber should be outputting. 

Olight M20SX Javelot

Manufacturer Specs/Features

  • Three brightness levels from 25 to 820 lumens, plus a strobe mode
  • Customized CREE XM-L2 LED with a smooth reflector creates a tightly-focused beam to maximize throw reaching out to 370M (1214 ft)
  • Multi-function click tail switch with momentary activation and on/off, along with quick access directly to the brightest level and the blinding strobe mode
  • Side switch to select modes with memory function to remember the last power setting used
  • Aircraft-grade aluminum body with anti-scratch type III hard anodizing, pocket clip, and crenelated stainless steel striking bezel
  • Reverse polarity protection to prevent improper battery installation and thermal management to avoid overheating
  • Length: 140mm; Diameter: 35.5mm; Weight: 125g

18650 18650 18650
820Lm 150Lm 25Lm
1.25h 3h 18h


So this is definitely the first case worth taking pictures of out of all the lights that I've received. Nice sturdy plastic with latches that lock in place. Although I saw /u/emarkd's M3SX-UT review having a similar setup, I had no clue that this light which is much smaller in size was also going to be coming with its own carrying case. Something like this would make a great gift idea because of all the little details that have gone into these Javelot lights.

Front of the Olight M20SX Javelot Case

Back of the Olight M20SX Javelot Case

Handle of the Olight M20SX Javelot Case

Interior of the Olight M20SX Javelot Case

The inside is even more impressive and instantly puts a smile on your face with the custom cut foam surrounding each item which the foam itself is covered in something like black velvet making it very presentable. I'm not a professional on types of fabrics so don't quote me on that one. With a closer look you can see that it includes a holster, lanyard, 2xCR123A battery sleeve, and my favorite, a diffuser cap. Not shown is the spare O-rings, glow-in-the-dark tailcap, the manual, and a small pamphlet showing all of Olight's models.

Contents of the Olight M20SX Javelot Case

Unfortunately the pamphlet is a tad outdated and although I didn't compare all models, I know there wasn't a single Javelot model in the pamphlet. I was actually really excited to see the diffuser cap since I have not owned one yet and have had it on a wish list for quite some time. The diffuser does a great job dispersing the light which would originally be almost impractical working up close because of the bright hot-spot compared to the spill. This combo eliminates the need for an additional light for close proximity work while still having the throw that dominates all others in its class and would make an excellent multi-purpose light for many situations.

M20SX Diffuser Cap

M20SX Diffuser Cap Example

So when I was first messing with the holster I tried putting the flashlight tail-cap first and I thought to myself about what a crappy design it was because the tail-cap didn't fit in the hole in the bottom and thought that maybe there was a mix-up with holster that I got. It wasn't until I was comparing the specs with a review of the old model that I noticed the light in the holster head first and realized how much of a blonde I really am. So at least we all learned from this, right? Fellas?

M20SX Holster

After reorienting the light everything looked much better and would explain the hole in the flap. I do gotta say though that the holster seems a bit big for the light but that's mainly because you gotta put the head down first so you're not able to achieve the slimmer design as others which are head up. On the sides there are small slots which I still couldn't figure this one out either and thanks to /u/emarkd, he pointed out that 18650 batteries fit perfectly inside. Can you tell that I'm not very familiar with holsters? It's actually quite nice that they're located on both sides which makes this a great work companion. You'll have to be creative though if you want to bring the diffuser along because that didn't fit inside the holster when I had it on the light.

M20SX with spare 18650s in the holster

Typically I'm not a fan of the cigar-grip ring near the tail-switch and usually remove those as soon as I get the light for the slimmer look but on this light it serves an important role if you're using the clip. As you can see in the couple of hours I spent on photoshop, the left arrow points to a special spot on the body that the clip fits snugly in place which in turn allows the cigar-grip ring to fit at a certain rotation over the clip where the little notch fits perfectly in place with the stub on the clip. Once combined, it 100% secures the clip in place along with securing the ring preventing it from rotating. Even screwed on clips have potential for failure but I have no doubt at all with this design.

M20SX crenelated bezel

This light does have a noticeable crenelated bezel and although it is removable, there was no access to remove the lens and no accessories that I could find online that would act as a replacement so ultimately you'll just be exposing the threads if kept off. Plus side, the diffuser fits more snug with the bezel off. Last thing to show is where the magic happens with the smooth reflector and the XM-L2 emitter which I'll talk about more next.

M20SX smooth reflector and CREE XM-L2 emitter


So now we get to the most unique part of these Javelot lights, the dome-less emitter. As far as I'm aware of, these are the first production lights to feature a dome-less emitter which I need to explain what's currently been going on with Olight and why I think they're still a work in progress.

If you want a higher resolution image of the dome-less emitter click that link, be warned it is 3.7MB in size.

So starting with the first Javelot, the M2X-UT Javelot has a factory dedomed XM-L2 emitter.-Selfbuilt;
the M3SX-UT Javelot has a factory dedomed XP-L emitter.-person278;
the M20SX Javelot has a dome-less XM-L2 emitter;
and the M23 Javelot also features a dome-less XP-L emitter. Now when I say dome-less I do mean that it does not have a dome covering the die but it does have a clear flat coating over it and the substrate as you can kinda tell in this photo.

So we have 4 different Javelot lights with 4 different emitter setups and so what's going on Olight? Well my assumption is that they wanted to still stay on track with release schedules of these improved lights but are improving the idea along the way which is why we see the latest Javelot models with the clear flat protected layer. This clear layer is actually important because typically when you dedome an emitter, you get a tint shift which can turn into ugly tints depending on which bin/tint you dedome. I know there's been some talk the dedomed Javelot models having a green tint to them and so with this clear layer, the tint will stay the Cool White tint and it will also extend the normal life expectancy of the die. Not like its life isn't ridiculously long already.

So getting back on track, the M20SX does have an increase of 270 lumens over the older model but the dome-less emitter is what plays a larger role in the throw bumping it previously from 197m to a whopping 370m now. With the head only being 35.5mm wide, this light easily out-throws all others in this size and even out-throws some lights that have slightly larger & deeper reflectors making this light a really impressive compact thrower. Using my light meter, I get the following results below:

Model Claimed Intensity Calculated Intensity Claimed Throw Calculated Throw
M20SX-UT 34,200cd 23,254cd 370m 305m
Predator v2.5 40,000cd 38,123cd 400m 391m
Nitecore P25 20,000cd 18,750cd 283m 274m


Surprisingly I got much lower numbers than what Olight claims and I retested my Predator just to double check my equipment but everything was fine. Then I though that maybe it was the CR123A batteries that Olight used for testing so I popped in two freshly charged Efest 18350 batteries and got 2 meters less of throw (which is negligible). So all in all I'm not sure why the numbers are so off vs Olight's specs. Considering it still beats the larger P25, I still consider this a nice thrower and it still out-throws all others in its size but was expecting the better claimed throw that was closer to the Predator's specs. I took some size comparison shots between the three lights and you can see how much smaller the reflector is on the M20SX-UT is vs other mid-range throwers.

Size comparison of Olight M20SX Javelot, ArmyTek Predator, and Nitecore P25

Size comparison of the reflectors of the Olight M20SX Javelot, ArmyTek Predator, and Nitecore P25

Here is a link to the full resolution of the reflectors size comparison.

User Interface

The tail-switch controls Momentary/On&Off while on the side of the tail cap there's a side switch that controls the modes along with instant access to Strobe. From On, press the side switch to cycle through the modes from Low to Hi and it will have mode memory. Also from On, hold the side switch for a full second to get into Strobe mode and will have mode memory as well when turned off. From Off, holding the side switch will instantly put you into Strobe but will only stay activated as long as you hold the button.

The tail-switch can also be used as a forward clicky. So of course it'll have mode memory but when you quickly do a half-press and then click on the second press it'll go to max output. If you quickly do two half-presses and then click on the third press it'll go to Strobe mode. It will not memorize these modes though when turned off and will default back to the previously saved mode the was selected by the side switch.


Looking at the manual it shows that it has a working Voltage of 3.0V to 8.4V which means we have multiple options. The most recommended battery to use is the 18650 battery which will give you superior runtime and will actually give you better runtime than what is shown in the stats. Plus they're rechargeable! The runtime stats are based off the use of two CR123A 1500mAh batteries. While CR123A batteries hold their charge very well, they fall a little short on runtime vs an 18650. If you want to get even worse runtime you can stick two RCR123A/16340/18350 batteries in it but these batteries will have about half the runtime of CR123A batteries.

Here are my results of the runtime of this light on Max output using a KeepPower 2800mAh battery:

Olight M20SX Javelot Runtime Graph

As you can see in the graph there is a step-down before the 5 min mark where it does drop down to about 60%. Not sure if this was timed or thermal regulated but it is quite common for lights to be designed as such. At the 55 min mark is when it is 50% brightness and slowly drops until at 2 hrs & 28 min it drops from 24% to 2% almost instantly. It was nice to see that it still maintained a glow of about 1-2 lumens at that point which would definitely be more useful than no light. Overall this far exceeds the 1.25 hrs that it is rated for and would have about an 18% longer runtime if used with 3400mAh batteries.

Personal comments

Although it shows 18 hours with the 25 lumen mode, I'm sure you'll get a much longer runtime using an 18650 battery which after looking online at other brands that have a ~25 lumen mode, they're reporting up to 50 hours in their stats. Although the 3 modes it has are nicely spaced, I guess the only thing I dislike about this light is the lack of a Moonlight mode. I wouldn't want to get rid of a mode but more along the lines of adding a 4th Moonlight mode. Having 4 modes is just a good minimum number that should be standard in the planning of lights to give the user more options.

Another thing that is kinda bothersome since I typically don't like the cigar-grip ring on my lights is that when removed it exposes the O-ring that is beneath the ring. You can see it here where it's just above the clip(there's two total). So if you do plan on keeping this off, take off the O-ring too and store it with the replacement O-rings.

The last thing which is a bit of a warning to others which hopefully they don't have this issue. My tailcap came loose but fortunately I own snap ring pliers to tighten it back up which I ended up having to do twice(not tight enough the first time). You can find snap ring pliers pretty cheap at Harbor Freight if worse comes to worst though.

Overall, I honestly love this light and everything that is included. This light has so many uses because of the throw/diffuser combo and with the case, you can easily store it in your car/RV/boat and any other places to keep an emergency light. This would be great for camping, Law Enforcement Officers, around the house, self-defense, and many others that I can't think of right now. I give the Olight M20SX Javelot a rating of 4.5/5.

We are making all of the images available in the full image gallery.

If you have any questions or comments about the review, join the discussion on my Reddit thread.

The M20SX Javelot is no longer available.

Share this post

← Older Post Newer Post →

Leave a comment

Please note, comments must be approved before they are published.