Lumintop FW3S Review

The Product

The light I'm looking at today is the Lumintop FW3S. This is a version of the FW3A that is made entirely from stainless steel instead of aluminum. Aside from that the two lights are almost identical. It runs on a single 18650, has three LEDs under an optic, and is controlled by an electronic tail switch. 
For those unfamiliar with this line of lights, they were designed by and made for the enthusiast community. The number in the name refers to the number of LEDs, and the last letter indicates the metal used. 


I've always said manufacturers should make more lights out of stainless steel - it's even harder than titanium and significantly less expensive, though it is heavier. When I said that I was thinking more of an AAA or AA light, but if it was going to be used for an 18650 light then an extremely compact one like this was an ideal choice. 
Just like the FW3A and the FW1A, this is a fantastic light. Most lights with tail switches are forced to use very basic interfaces and are quite large, but some very clever engineering means the UI on these lights is able to be both intuitive and completely configurable.
I still find the triple a bit too floody for my preference, but the popularity of this product line goes to show that not everyone shares my preferences. I find the lack of knurling on this one a bit of an issue given how tight the tail needs to be to make a good connection, but I think the stainless looks classy and feels like a tank. 

Physical Dimensions

The FW1A measures 92.7 mm long, 25.4 mm at the head, and 21.4 mm along the body. Without a cell, it weighs 115 grams. It's hefty enough that it feels as though a cell is in it even without one.
For comparison, here's a lineup. On the left is the FW3S, followed by the FW1A, YLP Unicorn 1.0, and Convoy S2+.


The light is made of raw stainless steel, which is really what differentiates it.
The bezel is smooth, and protrudes very slightly in front of the glass. This is one of many design elements made to keep the light as compact and sleek as possible.
The sides of the head are simple again, lacking even the knurling that was included on the original FW3A. Since this is where the light needs to be unscrewed for cell swaps, the smooth surface and be a bit challenging to get a good grip on.
The cell tube has a nice taper in the center, with the head and tail being the widest parts of the light.
The tail isn't really meant to be removed, since there's lots of little pieces to make this tail switch work. The switch is about flush with the tail. The light can tailstand, but the switch isn't very recessed at all and may activate in some pockets. The stainless steel switch boot matches the body perfectly.
Removing the head gives a look at the magic that makes this light work - in order to connect the switch to the driver, the power transfers through the main body tube (like most lights), but there's a thin aluminum inner tube that transfers the switch signal to the brass ring on the driver. The threads aren't anodized so there's no true mechanical lockout, but loosening the head slightly will prevent the switch from making contact and prevent accidental presses from being detected. On this light, I think the electronic lockout is a better option.
There's a short spring at this end of the tube, and another at the negative end. 

What's Included

Lumintop uses their standard understated packaging for these lights. Inside, you get:
  • The light itself
  • Manual
  • Spare o-rings
  • A card reminding users not to remove the tail
Although the tree-hugger in me wishes Lumintop would do away with the foam insert in their packages, they do a great job of fitting everything neatly in a small box while protecting it well.

Ergonomics and Retention

The general shape this light has, with a wider head and tail, is extremely ergonomic. Gripping the slimmer portion is solid since it can't slide off the two ends. For my hands, the longer head also makes the body fit better in a fist. It's worth noting that the raw metal is relatively smooth and slippery, so wet or cold conditions may be an issue for some.
The clip on this light is well designed as well. It's fixed to the light with a collar, so there's no risk of it getting pulled off. It's also not really intended to be removed, but the light will work without it. The clip doesn't carry very deeply, leaving a bit over 1.5 cm exposed, but it slides very smoothly over most pockets I've tried it with.
There are no other magnets, lanyard attachments, or other methods of retention for this light - though Neal and some other vendors are carrying a generic belt sheath that it fits into. Deep carry clips and lanyard rings are available as add-ons as well.

Modes and Interface

Aside from the compact size, the interface is the stand-out feature of the FW3S. It's controlled by a single tail switch, which many people prefer since it's always easy to locate without having to see the light.
Most lights with a tail switch have very basic interfaces, since the switch works by physically disconnecting power to the light. This makes it very difficult for the light to detect long presses and other complex interactions.
With the FW3S, the separate signal tube means this is an electronic switch, and it's running an open-sourced UI called Anduril. I won't cover every feature of that UI here (I don't think I could), but here's the basics that I use every day:
  • From off, a single press turns the light on in the last used mode
  • From on in any mode, a single press turns the light off
  • From off, press and hold to turn the light on in moonlight and smoothly ramp up the brightness from moonlight to high
  • From on, hold to ramp up the brightness to high
    • Tap then hold to decrease the brightness
  • From off, double tap for high
    • From on, double tap for turbo
    • Double tap again to return to the last used mode
  • From off, tap 4 times to lock the light out
    • In lockout mode, hold the switch for momentary moonlight
    • In lockout, tap then hold for momentary low
    • In lockout, tap 4 times to unlock
There's a ton of features, but it really does all the basics well. The two levels of momentary while the light is locked out are an absolutely fantastic feature - I've loved momentary moon in lockout since I first tried it, and this is even better.
There's boat loads of configuration as well - you can change ramping for stepped modes, change the upper and lower ramp limits, and so much more. My one qualm with this UI is if you pick up the light and start clicking it on and off for fun, you might end up changing a setting or in a mode you didn't intend to be in - but in most cases, removing the head and re-installing it will get you back up and running.

Light Quality and Beam 

This light uses 3 LEDs being a triple optic, with a variety of choices for the emitters. I have the XP-L Hi in my review sample. Using three emitters in such a small light means a lot of output, but the very small space in the optic to direct the light forwards gives a very wide beam that doesn't reach as far as I tend to like.
Compared to a 4500K E21A, the beam from the XP-L Hi I have is a bit cooler and greener, but still very even across.

Which LED should you get?

For those looking at the options available on Neal's site and unfamiliar, here's a brief rundown of the emitter choices.
The Luminus SST-20 4000K is the one I'd probably recommend for most people. This LED is a slightly warm-neutral temperature. It has high CRI, meaning it accurately shows colors and won't wash them out (a common problem with LEDs). Since the LED is so small, the light is very throwy (it gives a lot of distance), but the output isn't quite as high (less lumens) than some other options.
The Cree XP-L Hi is the option I have in my sample. This will also have a very throwy beam, but it's not high CRI and may wash out some colors. Output will be a bit higher than the SST-20. There are three of these available - the 1A is a cool white (a bit bluer), 3D is neutral, and 7A is warm (a bit more orange-y).
Finally, the Nichia 219C 4000K will have a wider beam than the other options, with a more even tint and higher CRI - but less output.

Power and Runtime

The light is powered by a single 18650. There are springs at both ends of the cell tube, but since the light is made to be as short as possible only unprotected cells will fit. Some button tops may fit, but for the best results use a high drain, unprotected, flat top cell. The Sanyo NCR18650GA is what I use in my lights, and what the runtime tests below were with.
Runtime was tested without cooling, so this high output lights steps down very quickly. The runtime is fairly stable after the initial step down - but at 10 seconds it's already 3 times less than at turn on, and it steps down to about 20% for the remainder of the run.
Zooming in to the first 10 minutes shows the step down a bit clearer. The FW3A was added for comparison, and we can see that the aluminum sheds heat better and allows about twice the time before that giant step down to a lower mode.



  • Stainless steel body is stylish and durable
  • Number of emitter options to choose from, including multiple high CRI options
  • Incredibly flexible and well thought out Anduril UI with incredible double-momentary lockout
  • Fantastic design and ergonomics
  • Great clip
  • Good thermal regulation


  • Turbo output is higher than the light can handle for more than a few seconds
  • Button is prone to accidental activation
  • Stainless steel body again - some people won't like the added weight

Notes and Links

This product was provided free of charge from Neal's Deals. I was not paid to write this review, and have tried to be as unbiased as possible. I had some input into this light's design, and I'm sure that impacts my ability to remain unbiased.
Product page on Neal's site - use code BLFFW3A for 20% off.
Accessory page with a few different clip options and glow gaskets (the short tubes should work, but won't match the SS head and tail).