Overview.
The S3 is Ultrafire’s answer to the “flat flashlight” trend, and it’s a good one. It combines normal white light with UV light and a red laser, all in a solid compact and totally pocketable frame. The UI is simplicity itself. Its flat design is naturally anti-roll. A strong magnet in the tail lets it adhere to ferrous metal surfaces for even more flexibility.
For full disclosure, this is my first of this type of light, so I can’t quite compare with other offerings. My first impression, though, is to be so wowed by it that I just had to show it off that night. 
What’s In The Box?
The box itself is a rather nice 2-piece cardboard box with nice graphics and some specs printed on it, almost nice enough to be a presentation box. Inside is a foam liner that protects the light, a usb charging cable, printed manual, translucent liner, and of course the light itself.
Features.
The S3 features a sleek rectangular package sort of like a long cigarette lighter. This is supposed to make it more convenient to carry in a pocket vs a regular cylindrical light. It also features a bolt-on 2-way deep carry clip, so it can be clipped as usual inside a pocket, or possibly in reverse to a baseball cap’s visor to use as a headlamp. It also has a pretty strong magnet in the tail to be able to stick onto ferrous surfaces.
The business end of the light has a standard white LED that claims 1200lm on turbo, plus a 365nm UV LED for fluorescing minerals and other fascinating things, as well as a red laser pointer that’s great for presentations and other things.
It has a nonremovable 1500mAH LiPo cell, and the light is usb-C chargeable.
The User Interface.
There is a large rubberised button on the side of the light that provides main functions. Press and hold from off to turn it on. Press and hold from on to turn it off. Press momentarily when on to cycle through modes, if applicable.
There is a slide-switch on the side to select white light, UV light, or red laser. It can be switched to select when on or off.
Red laser and UV are single mode, simply on or off. White light has 4 levels of low/medium/high/highest. Clicking when on does nothing for red or UV, but cycles through the 4 brightnesses for white. I noticed that as the cell “wears down”, you only get 3 brightnesses, ie, it excludes the highest mode. I haven’t burned down the cell so far as to see if it further limits itself to 2 levels, but I suspect it does. So that also implies it’s regulated, and isn’t just ratiometric for 4 levels no matter what.
Doubleclicking when off locks the light. Any activation of the switch when locked simple gives 2 “blips” of white light to let you know it’s locked. Doubleclicking when locked turns on the light.
It’s really that simple! True, press and hold to turn on/off bucks the trend of other lights where it’s single click for on/off, but this light is designed to be carried in a pocket, and a press and hold is less likely to be done accidentally when the light is in your pocket, than an accidental click. You get used to it very quickly.
Battery Status.
The main switch also provides a battery status function. When off, clicking it will have it turn on for 2 seconds showing the battery status in color. Green means fully charged, from 80% to 100%. Yellow means adequate charge, from 20% to 80%. Red means insufficient charge, from 5% to 20%. Finally, flashing red means “feed me now!”, or less than 5%.
I only managed to get it into the yellow.
First Impressions.
First impressions of the light are great. Right from opening the box and looking at the packing, through checking out the light itself.
Despite the small size, the light feels solid. Definitely not a plastic-body light, that’s for sure! I’ve seen lightweight plastic-body “keychain lights” of sorts, and the S3 definitely isn’t like that. This is a solid substantial light.
Finish is a great satin-black anodisation, with no nicks or voids anywhere. The etched sides are surprisingly grippy without “biting” or being sharp on edges or corners.
The steel bezel around the front glass is a nice touch. It’s raised just enough to protect the light and glass without protruding too far and collecting pocket-lint.
The magnetic tail is powerful and grabs pretty much everything around, sometimes when you don’t want it to. 
However, it’s also very smooth, and trying to stick it to a slick vertical surface like the side of a bathtub, it’ll just slide down. I wouldn’t recommend deliberately scuffing the tail to make it more “frictiony”, so if need be, maybe a mild adhesive or just something sticky?
The flap covering the charging port fits really well. It takes a little effort to pry it open, but closes easily and stays closed.
The main switch is nice and stiff, and requires deliberate pressure to activate. It’s raised somewhat, so it isn’t immune to accidental activation, but being stiff minimises that.
The side switch to select white/UV/laser has a positive detente to let you know which position it’s in, but given how much switch-travel there is, I’m not sure how waterproof it might be. I don’t think splashed water would hurt it, but without knowing its “waterproofness”, I wouldn’t dunk it.
Pretty sure people know I generally dislike clips, but this clip isn’t bad at all. It’s nice and springy, and the bend by the screws is wide enough to clip onto the edge of a jeans pocket. Also, given the small size of the light and the natural curvature of your fingers holding the light, the clip doesn’t “bite” or pinch your fingers. That’s one reason I dislike clips on regular-size lights, but here, it’s not an issue. Your fingers curve right over the clip pretty much without touching.
So? First impressions are great.
Usage.
Oh, I put this light through the paces! I usually keep lights on low except when more brightness is needed, so using the light pretty extensively, I still only managed to get it into the “yellow” of the cell’s charge. So battery life should be pretty good unless you turbo everything in sight.
Charging works well, red ‘U’ on the main switch when charging, green when done. Simple.
Yes, longpress for on/off takes some getting used to, especially when going back and forth between the S3 and other lights that have single-click for on/off. I know some people will hate it, but I think the advantage of few if any accidental activations in a pocket make it a worthwhile tradeoff. If I were to use the S3 as my one-and-only-light, I’d get used to it in no time. It’s only the back and forth between different lights that can “reset” your getting used to it.
The Beam.
The beam itself (white) is the usual for high output / high efficiency emitters. Brighter settings are neutral white. The box says 6500K, but I doubt that’s true. That’d definitely be on the blue end of the spectrum, and this is neutral.
The lowest brightnesses will be slightly green-tinged.
The beam shape is a decent size hotspot and lots and lots of spill. It’s pretty good very close-in and very good at intermediate distance. Farther out, you’ll have to brute-force the brightness by switching to the higher settings, but that’s to be expected.
The reflector(?) on the UV emitter is faceted, like many MR-type halogen bulbs, to give a nice even dispersion of light. So this works extremely well close-in. Great for checking bananas in the supermarket!
The laser is a clean round dot and pretty intense.
Grexes.
Few, if any. With an even stiffer button to resist accidental activation, could the light be single-click for on/off? Maybe. But then again, people might then complain that the button’s too stiff. You can’t win.
Any way to add a direct-to-moonlight mode? Like maybe quick-click then longpress? Possible. Lowest is fairly bright, so flicking it on in Mystery Mode in the dark might just blast your night-vision. A guaranteed shortcut to moonlight or at least lowest might be nice.
A “better” emitter, as in less green, higher CRI, more pleasant tint? Possible, but you’d probably lose some lumens, trading quality for quantity.
That’s really about it. Everything else about the light is quite nice.
Final thoughts.
All in all, I’m hella impressed. This is my first “flat” light, and I like it! Everything seems to be well thought out, hardware-wise. The build, fit and finish, brightness, performance, etc., are quite nice. The ergonomics of the switches and the light’s “hand-feel” are great.
The dual-switch design is nicely done, too, making it a breeze to select white, UV, or laser. No need to Morse-code a command via a single switch to select emitters.
The S3 includes a decent clip and a strong tail-magnet.
The light also locks, so you can take that step to make sure it doesn’t accidentally turn on.
Even the box is almost presentation quality to be able to give it as a gift without being embarrassed.
Love the UI or hate it. I suspect this would be divisive, but it is what it is. Me? I got used to it just fine.
So? It’s a keeper.
Bonus!
You can get a .pdf version of the manual on the Ultrafire site.
Apologies in advance, but I haven’t been able to get pix off my phone. Looooong story…
