you can buy this flashlight here at
Aliexpress
Amazon
As I see, pioneer of this sort of small rectangular keylights (I mean popular pioneer, as I assume there could be some other models before) was Nitecore Tube, which popularity pushed other manufacturers to the same direction. So, now there are some quite similar products :Nitecore TIP, recently released Manker Lad ,Yarkiy Luch Scorpion that was issued in collaboration with forum.fonarevka.ru и and hero of this review - Mecarmy SGN7 .
Ok, what we are promised to get in this flashlight.
● Designed for everyday carry, 5 beautiful colors are available
● CREE XP-G2 S4 LED, max 550Lm in such a tiny size
● Instant Alarm, Strobe and Turbo for emergencies
● USB rechargeable, charges in just 1 hour on any USB port
● 5V 1A power bank function to save your phone from cutoff
● Features charging and fully charged indicators
● Waterproof in accordance with IPX-5 standard
● Pocket clip, keyrings and lanyard are included 
PACKAGE AND APPEARANCE
As Borat Sagdiev said, “I like, very nice”.
Brown paper box with modest and accurate design.
Package includes also lanyard, English manual, short micro-usb cable and 2 spare keyrings of different size.
Size of SGN7 makes a controversial impression. On one had it is quite compact,comparing with regular EDC-lights, on the other – it is significantly larger than Tube - Product size (L x W x H): 7.50 x 3.40 x 1.40 cm / 2.95 x 1.34 x 0.55 inches
SGN7 is made from aluminium and has wide notches on sides for better grip. At this point , I`ve got no complaints about it`s quality – it doesn`t look and feels like cheap product.
None of sides is empty – 2 buttons on top-side, 2 usb-sockets on opposide sides, removable clip at bottom side. Usb-sockets are tightly covered with rubber plug.
I don`t understand Mecarmy`s decision to install SMO reflector instead of OP. May be that`s for large marketing numbers like “55m beam range!”
I unscrewed SGN7 and saw this. Ok, looks like it was soldered and assembled accurately.
Alarm speaker is attached to back side (the one with clip), so when you turn it on, try not to cover this side with fingers.
I`d like to mention that heat dissipation goes through the whole electronic board (here i`m not sure that i`ve picked proper English words, sorry). And as you can see, there is a gap between those 2 parts of body with holes for screw and electronic board. I suppose manufacturer could add some thermal paste to fill this gap and improve heat transfer right by the LED. Of course, once there is 30 sec stepdown from turbo + thermal regulation of further brightness level (it`ll be in between HIGH and TURBO) body will not get really hot. But anyway, I see here an opportunity to improve it.
UI
Yeah, I like it. This part of SGN-7 is convenient.
There is an instant access to LOW, TURBO, STROBE and ALARM.
The only thing that I don`t like is that you have to press button really hard, that may be not that easy to 2-3 quick presses. But, again – if it wasn`t so, SGN7 could be turned on in pocket with just light pressing buttons (that`s not so bad in case of light, but imagine you lean to wall and ALARM mode starts)
SGN7 IN ACTION
Pencil test revealed PWM-shimmering in all the modes except TURBO.
For it`s compact size, SGN7 is really bright. Turbo has 30 sec stepdown and thermal regulation, so finally it will be somewhere in between high-turbo (depending on temperature). I find brightness levels convenient for most of close-range needs – to illuminate path in front of you, to look around in garage and see where is all the stuff on shelf etc. You can see speeded-up stepdown in youtube video below.
But of course for such a price i could expect something neutral and hi-CRI
What about practical real beam range, i`d evaluate it as 15m. Within this user can be sure that he or she`ll see everything in TURBO mode
Alarm is quite loud not to only give a signal “here I am!”, but may be also to frighten away a hooligan. It is 110 db, but Mecarmy manager said they`ve improved it and it`s 120 now. I think it will be more useful to instal some kind of ultrasonic beeper to drive away dogs (and cats, and mosquitos, and tax inspectors).
In powerbank mode SGN7 could provide 380mah with 0.62А. USB-tester has shown 578 mah with maximum amperage of 0.95А.
https://www.youtube.com/watch?v=V6qPfVFUXCc&feature=youtu.be
OVERALL
What about functionality – SGN7 has reasonable choice of brightness levels, convenient UI and really bright TURBO. Powerbank mode can be real, real help in some situation. And may be alarm, as well.
What I don’t like is PWM shimmering, I believe that for this price manufacturer could get rid of it. SMO reflector is a controversal choice, i`d prefer OP or TIR.