The flashlight was sent to me by FlashlightBrand for review.
Here’s the product’s link for more info: Mateminco CSF-04
And a link to the Mateminco Collection
The Mateminco CSF-04 comes in a plastic box.
It’s seated inside some foam to protect it during shipping.
There are plenty of different colours that the CSF-04 comes in.
I’ve chosen to go with the ‘Starry Blue’, which looks very nice.
Since this is a key-chain light, here’s a picture of it on my own set of keys.
Overall it’s pretty compact and feels inline with the size of regular keys.
The light is operated via an e-switch that’s mounted on the lower portion of the head.
The switch is covered by a rubber boot and is quite tactile.
Opposite to the e-switch there’s the charging interface of the light.
The USB Type C port is covered by a rubber flap to keep dust and moisture out.
Once plugged in, an indicator LED mounted on the head of the light will light up.
The head of the Mateminco CSF-04 houses a TIR reflector along with a Luminus SST-20 emitter.
The tail of the light contains a loop that can be used to install a key ring.
Along with main emitter, the CSF-04 also incorporates 4 side mounted emitters (Red, Blue, UV, RGB).
Red
Blue (It’s really messing with my camera 
)
UV
And here’s a GIF of the RGB.
User Interface
The Mateminco CSF-04 comes with a very convenient firmware.
Here’s all the supported actions:
Turn on/off: Single click.
Ramp up/down brightness: Long click. Releasing and long clicking again will change the direction of the ramping.
Turbo: Double click while on.
Strobe: Double click while off.
AUX mode: Triple press. Once in AUX, single click to alter between UV / Red / Blue / Pulsing Red / Pulsing Blue / Pulsing Red & Blue.
Battery Voltage Check: 4 clicks while off.
Lock / Unlock: 5 clicks.
RGB flash on/off: 6 clicks.
Factory Reset: 7 clicks.
Output
Turbo: 245 lumen @ turn-on
Low: < 1 lumen
As we can see, the CSF-04 produces some serious output for a keychain light.
Since the flashlight implements infinitely variable brightness, the user can easily select any output between Low and Turbo.
FInal thoughts
Overall the Mateminco CSF-04 is a great keychain light.
I’ve been carrying it for a couple of weeks and so far it’s been a great addition on my keychain.
I’ll make sure to update this thread in case I find any issues with it after using it long term.