Astrolux S43 (Quad Nichia LED, 18650/18350, USB Recharging, Hand Warmer Feature)

Astrolux has a small quad LED light, the S43. This builds on the the similar S41 and S42 line of lights. The S43 is a revised design, let’s see what’s good and bad about it. Thanks to Banggood for sending this to me to take a look at today.

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YouTube Version of this Review:


Packaging is pretty similar to other Astrolux lights of this size. It’s a brown paper box, with a bowtie cut in the middle almost. On the side is a sticker with the model and LED option on it. Inside the light is protected in foam. The S43 comes with lots of accessories that were once addon items in previous version. It now comes with a deep carry pocket clip, 18350 tube, lanyard, and glass breaker/skull cracker spike. It does come with a manual but it’s not quite accurate, it seems to be largely recycled from the S42.


The head of the light has a non removable crenelated bezel that’s moderately aggressive. Underneath it has a small quad optic, similar to the S41. Below that the light has it’s button that glows green (Can be configured to turn off), surrounding the button is a copper/bronze colored bezel. The sides of the driver are a larger piece of milled aluminum with small heatsinks on the sides. Opposite the side button is the Micro USB charger port and cover. The port is fairly deeply recessed but I didn’t have a problem accessing it with a standard cable. The charger cover does have a tab that I seem to catch with my finger when the light is in use. It’s more annoying than functionally wrong.

The body tube is fairly smooth with no knurling ot texture for grip which is unfortunate.. There are indents at either side for the clip. The tubes are not reversible. It looks very similar to the battery tube on my Emissar D4. The S43 also comes with a 18350 tube which is nice that it’s not an additional purchase. The shorter tube is the same just shorter. It also has areas for the clip to connect. Threads are acme cut, and there is no spring in the head. This causes a bit of a problem if the light is jolted as it loses connection and doesn’t come back on by default.

Glass Breaker/Skull Cracker Spike. The tailcap of the light has as an optional (included) steel spike that can be screwed onto back of the light. For me this is more of a gimmick than useful. Yes it could be used a a self defense option, or used to break glass but the last thing I want is this spike sticking out of my pocket or poking a hole in my bag. Thankfully it can be removed and the threaded hole could be used to connect to a tripod. Personally I would get more use out of this if it was a magnet instead. The spike screws into a ¼ 20 insert. The insert can be removed and I am guessing it’s roughly a ? screw but I ma not quite sure. With the insert screwed in it doesn’t tail stand very stably.

Other versions of this light are also available. There is a version where the head portion is copper, and a red/green anodized version for the holidays. There isn’t a stainless steel model yet but I wouldn’t be surprised if we see one eventually.


I measured length at 122mm without the spike or threaded adapter with the 18650 tube. Maximum diameter is 30mm at the head, and minimum diameter is 24mm on the body tube. Weight with battery and clip is 141.5G


The light comes with 2 versions, a cool white Cree XP-G3 LED and a Neutral white Nichia 219C at 5000k which is what I have. Tint on mine seems a little warmer than 5000k but I don’t mind. The light is capable 2100 lumens on it’s turbo mode.

Beam shots has a warm hot spot in the center that a gradual fade as you move from the center. For a quad light it’s fairly round. At short distances you notice a few artifacts but these mostly fade away at 4-5 feet.

Output & Runtime

The S43’s runtime and heat output is a little disappointing but roughly what I would expect from a small diameter quad Nichia light. So the light is capable of a maximum of 2100 lumens and has a ramping UI as it’s primary UI. I did my testing with a Sony VTC6. In turbo the light ran for just slightly over 1 minute before starting it’s stepdown. At the 1 minute mark I measured 113F at it’s hottest point. That is pretty warm very quickly. Between 1 and 2 minutes the light stepped down twice to about 10% relative output. This is a very big decrease in output really quickly. At 2.5 minutes the light reaches it’s comfortable longer term output at about 5-8% relative output. After 6 minutes I measured the light was 95F. It held this low output out to 375 minutes where the light stepped down a few more times to run at bear minimums. I stopped my runtime test at a little over 500 minutes. Overall I felt like while this light gets bright it’s almost unusable because of how fast the light steps down and how much it steps down. At least with it’s ramping UI you can adjust the output to exactly where you want it. Performance with a quality 18350 should be similar just with a shorter overall runtime. The light does have Low Voltage Protection which is good since you want to run it with a unprotected cell for the most output.


This light has one single side switch (A change from the S41), and uses NarsilM ramping firmware for it’s UI. By default it comes with the Ramping enabled but there is a stepped mode if you prefer. For my testing I left it in the default ramping UI. Ramping is fast taking just under 2 seconds to go from the lowest to highest mode. It gives a brief flash at the top to let you know your there, and does it at the bottom too, although thats hard to see at such a low output. I will like to the manual in the description so you can look at the other options, it looks a little complicated to adjust but after you have done it a few times it’s not too bad.

Link to Mode 1 Manual

Link to Mode 2 Manual


The light does have onboard recharging via MicroUSB. I measured the speed at 0.72A and this resulted in my 3000mAh Sony VTC6 taking 5 hours and 2 minutes to charge to completely full. A little slow for an 18650 but a very safe speed especially if your using it with a 18350.


  • I like that it now comes with the 18350 tube and a pocket clip for the price. (They used to be add on items)
  • Nichia LED option
  • NarsilM Firmware (Ramping UI with lots of configurable options)


  • Step downs from Turbo are large and the light gets beyond warm
  • Breaks connection (Light turns off) if using flat tops and the light is jolted (Doesn’t come back on)
  • Smooth body


For the price this is one of the least expensive Quad LED lights you can get usually (when on sale, see youtube for a coupon). For its size it puts out a ton of light, but at least in this S43 the step down from Turbo to high is quite large and it gets hot! Turbo is more of a momentary because it lasts so little time. I wish it had a bit more grip and didn’t lose connection if jolted hard (Like if using the glass breaker), especially for a light that advertises itself with tactical features.