[Review] Sofirn C01s (1xAAA, twisty, SST-20)

Sofirn C01s

MSRP: $11 ($9 on AE)

Manufacturer page: N/A

Store link: https://www.amazon.com/gp/product/B07PM4KZVZ/
AE: https://www.aliexpress.com/item/32952525303.html

I was sent this light to review free of charge but, as always, I've tried to be as unbiased as possible.


TL;DR

The Sofirn C01s is a AAA twisty keychain light. It's an improved version of the original C01, which used a neutral white high CRI 5mm Yuji emitter and only had one mode. The C01s has a 95 CRI 4000K SST-20 behind a TIR optic, and it has two modes.


Album link

Packaging

The C01s comes in a plain cardboard box with a label. The contents are padded by a piece of foam at the bottom.

Contents

The box contains:

  • Sofirn C01s flashlight
  • Clip
  • Manual
  • Two spare o-rings
  • Split ring

Build

The C01s is very typical for a twisty light. There's a head and a body, and that's all. It comes in black, blue, and red. I got red because I didn't have a red flashlight.

Being an AAA light, it's a bit longer than other keychain lights, but it's shorter than my car key. The overall machining quality might be slightly less than Sofirn's other stuff, or it could just be that it's a smaller light and the flaws stand out a lot more than they usually would.

The tail end of the body tube has a few holes milled in it. The circular hole is for a 5mm magnet, and the other hole is for a tritium vial. Between these is a through hole for the keyring.

The keyring can go around the magnet hole, which allows the light to tailstand even when the keyring is attached. I don't have any 5mm magnets, so I was sadly unable to test how well it sticks to stuff.


The majority of the body tube is covered in diamond knurling, and there's a clip groove at either end.

The head end of the body above the clip groove is a smooth section, where "Sofirn C01S" is silkscreened on one side and the CE, RoHS, and "don't throw this away" marks on the other side.

There's a spring inside the body tube. It seems like it's just been shoved down there, held in by friction.


The head of the light is made up of the bezel, pill, optic, and a gasket.

There are two o-rings on the pill, and coupled with the gasket in the head they give the C01s great water resistance. The positive end of the AAA contacts the center of the driver (no spring), and the outer edges of the PCB contact the body when the head is tightened.

The emitter sits behind a TIR optic, which gives it a very nice beam.

One potential issue that I've seen in my testing is the pad that the AAA button contacts. It's already starting to wear out. This isn't due to any fauly of manufacturing, it's just that you have to twist the light to turn it on and change modes, and the AAA will be rubbing against that pad every time you twist the head. A thin brass disk in that spot would have significantly increased the durability of that contact.
When I first got the light out of the box and started messing with it, the head came unscrewed and the pill stayed in the body tube. This happened in the first minute of playing with the light. I'm pretty sure that this can be prevented by keeping the body tube threads and o-ring more lubricated than the head threads and o-ring, and not tightening the head a whole lot.

Clip and Keyring

The C01s comes with a clip installed. This clip sits securely in either of the clip grooves on the body. For clipping it to a pocket, tail up carry makes the most sense. With the reversible clip though, it makes a great hat light.


The keyring is a typical split ring. It loops through the hole in the middle of the tail. It can lay flat which allows the light to tailstand and stick to stuff with the magnet (if installed) even with the keyring attached.

Battery

The manual says that the C01s takes either an alkaline or NiMH AAA, and it can take those, but it can also of course take an Energizer lithium AAA, and it will work with a 10440 cell. With the 10440 both modes are significantly brighter, but it also heats up faster. I don't think it has good enough thermal properties to run on a 10440 safely. Also there's no LVP.

Modes and UI

The C01s has two modes: Low and High, which are advertised as 3 and 100 lumens, respectively. Tighten the head to turn it on high, then loosen and tighten again within 5 seconds to go to low. After 5 seconds of being off, it'll come on in high. I'd normally prefer that it come on low by default, but the 100 lumen level on this light is great for general use.

Beam and Tint

The 4000K SST-20 combined with the partially frosted TIR gives the C01s a beautiful beam. It has a fairly wide hotspot, a little bit of spill, and absolutely no tint shift. Being 95 CRI, it also makes things look really nice. I couldn't be happier with the beam. Here it is compared to my 4000K 90+ CRI 219c Skilhunt H03.

Modding Potential

Disclaimer: Do this stuff at your own risk. If you mess up and break something, that's on you. Also, doing any of this will totally void your warranty.

Driver: Proprietary
MCPCB: 9.75mm, with little wings that come out to 12mm

An emitter swap would be possible, but why would you want to do that?


Bottom line:

Pros

  • Cheap
  • Beautiful beam
  • Lots of options for retention

Cons

  • Some visible milling marks
  • Positive contact pad wears quickly

Thanks for reading my review! If you have any questions about this flashlight, I'd be more than happy to answer them.

Accidentally posted early. Will finish formatting in a bit.

Thanks for posting this review!