Here is a little review about the sunwayman C13R i got from Fasttech (link) as a sample. I was curious what this little light can do because i always liked the design and color of it.
Here are some measurements i did (budget DMM)
Here is what you get with the light. The package is standard but i like the color choice. You get a lanyard, spare o-rings for the tail and lens, a manual and an adapter for CR123 batteries because this light is wider than usual for 18350 usage, even though i had no problems with 16340s without the adapter.
Here is the 360°view of the light.
Now to the machining of the light, there were a few scratches and small notches but that doesnt mean your copy will be like that. The silver anodizing and the surface is matte, i like the grey color of the light. Under the silicone switch cover are two LEDs, more about that later. There is no real knurling but the surface feels rough.
One of the features of the light is a tripod mount as you can see here. Im not a big fan of flashlights as studio lights but this light seems a bit small for that purpose. Maybe i would have prefered a magnet instead of a tripod mount. With a flat tail like that the C13R can tailstand without any problems. It also has three large lanyard holes.
Out of the package the threads were super dry and squeaked like hell, so you will need some silicon grease. I guess the rough matte surface is one reason for that.
The walls are more on the thicker side.
A look inside, the C13R has only one spring in the back, no spring in the front. The PCB is blue, if you look at the sunwayman page you will find a C13R with a green PCB
The C13R comes with a XM-L2 U3 emitter with 380 lumen at turbo, 180 lumen at high (2 hours), 50 lumen at medium (10 hours), 10 lumen at low (60 hours) and moonlight mode with ?? lumen 
, its not stated in the manual. The working voltage is 2.8V-4.2V according to the manual, more on that later. A reverse polarity protection is build in as well. The light has a smooth reflector and a pretty wide stainless steel bezel which is not glued in.
Because of the larger head it has a more focused beam compared to other CR123 lights.
A tint comparision with other lights, its cool white but a bit warmer compared to the typical Olight CW.
Edit: the picture above doesnt show the tint color that good, compared to other warmer tints it looks a bit to "cold". Here is a color comparision with a real CW light and you can see the difference much better.
Nitenumen E01 on the left
different apperture
Compared to other CR123 lights its a little "fatty" 
but its gorgeous looking in my mind.
Im sorry but i had to do some beauty shots, i guess thats called "flashlight porn"?
The moonlight mode, when my sphere is ready i will measure the output, its not stated in the manual
Of course the lens is coated
Now enough with that, lets see what the charging function can do. There is no spare rubber cover in the package, so be careful with it. The light charges with 0.3 amp and it finished at 4.17V.
During charging the switch is red and when the charging is finished it will show green, the charging process is completey stopped when the light shows green unlike another light i reviewed recently.
to the UI:
you switch the light on with a single click, i have to say that the sunwayman website declared this as instant turbo which i can not confirm. Its true that the light will start in turbo after a single click from off when you put a new battery in or after a mechanical lock out but normally it has mode memory and it will start from the last mode used, so its not really a shortcut for instant turbo. Maybe there is a secret timer and the light will start in turbo after XX hours again, i didnt tested that.
from on you just long press the switch to ramp up trough your modes from a low to high loop. The moonlight mode is not in that loop, its activated by a long press from off. The moonlight mode is not part of the mode memory feature as well.
Strobe is activated by a long press from on, from strobe you can again long press for SOS and another long press for a beacon signal.
There is also an electronical lockout function, it is activated from on or off by a quick double tap but you have to hold the switch after the 2nd click!, its unlocked in the same way. So its like a click followed by a click+hold.
Here is a little runtime test i did with the light. Something unpleasant happend, according to the website the C13R should have a low voltage cut off but its obviously missing in my sample, my unprotected 16340 Battery had 1,99V after the 2nd test. I have to mention that i did the runtime test before with a protected 16340 cell and the protection board of the battery kicked in, i thought the C13R internal cut off was maybe at 2.8V (because the manual says working voltage 2.8V-4.2) and the battery protection kicked in before the low voltage protection of the light. Thats why i tried it again with an unprotected battery, i was sure the light had that low voltage cut off function but obviously not, maybe my copy is defective. I had to reset the protected cell in my xtar charger, the internal charging function of the C13R couldnt charge it anymore.
Another thing that worried me is that there is no low voltage indicator, the switch is not used to indicate a possible low voltage, thats a bummer because the red and green indicator LEDs are already there.
white wall beamshots (no moonlight)
As a gif
outdoor beamshots
As a Gif
The positive thing about this light is definately the design, the ability to use 18350 batteries and the good internal charging function. The tripod mount is a neat feature but not that important for me and maybe other people as well. Another good thing about the light is the absence of visible PWM unlike some other lights ive reviewed recently.
I always like safety features in flashlights and the lack of a low voltage cut off is not so nice, the same counts for the missing low voltage indication. Some will also argue about the relatively low output but i would personally accept that because of the low capacity of those type of cells, the C13R stays totally cool on turbo but there is a step down after 3 minutes (steps down to high mode, 180 lumen). Maybe my copy is just defective, if not i hope those things mentioned above can be solved in version two of the light : ) I would recommend protected cells for this one if other samples are identical to mine.
