Very good - I agree. But susceptible to scratches. There is no glass. Only optics.
LEDs:
And one more comparison (wuben-left, carclo 10621-right):
It is the same TIR as the one in the FireFlies PL47.
EDIT : After doing a quick search on aliexpress then Alibaba for “4 in 1 led lens”, this one looks like to be a close match.
It’s easier and cheaper for flashlight manufacturers to use local parts instead of importing them, then I would assume that FireFlies and Wuben used this one or a clone of :
Considering the lower quality of the one used in the PL47 with mold defects, it was probably a clone or a “QC rejected” batch.
Ugh so they aren’t interchangeable?
Just got my light today. The fade-off is definitely weird, but I think it’s growing on me. Tint is perfect! Definitely a sturdy light, and the magnet is plenty strong for everything I’ve used the light with. Thanks for the GB the!
Maybe that fade is working similar to a soft start …
I wonder if it was designed that way, or resultant.
Probably a resultant of the boost driver circuit that gradually discharged itself once the power is cut off. I’m not sure of that though but seems logical if there is a capacitive effect involved.
EDIT : A pity that there is no glass lens in this flashlight. :person_facepalming:
I think the fade out may be due to the phosphor that is used. Fluorescent tubes have a fade out, or decreasing afterglow that is similar.
All the LH351Ds I’ve used have a slight glow for 5+ seconds after being turned off.
My Zebralight have a a much more noticeable “fade” when shut off too, always assumed it was the boost driver.
This board could be configured as 6V or 12V but not sure if it could actually be modded to fit with no screw holes.
http://www.mtnelectronics.com/index.php?route=product/product&path=63_64&product_id=849
CCT taken at “High”
CCT = 4816K (Duv 0.0040)
Color Rendering Index (Ra) = 90.1 [ R9 = 52.4 ]
R1 = 89.7 R2 = 91.2 R3 = 92.9 R4 = 91.5 R5 = 89.7 R6 = 88.4 R7 = 93.6
R8 = 83.8 R9 = 52.4 R10 = 80.1 R11 = 92.0 R12 = 71.8 R13 = 89.8 R14 = 96.7
Yxy: 2294.589942 0.351585 0.364922
Moon: 0.57lm
Micro: 14lm
Low: 56lm
Mid: 272lm
High: 1333lm
Turbo: ~2680lm at 30s
Tail standing for like ~8-10 minutes on turbo got about 930lm
Thank you Contactcr for the values! That’s interesting, it confirms my impression that the CCT is a slight bit under 5000K and the CRI right around 90.
I just received mine today and this is a great light! I’m already liking it very much!
I definitely appreciate the ability to run on high for lengths of time, running a battery with enough capacity to support that. The Moon is a great level, and I’m very happy about the nicely logarithmically spaced brightness levels!
Just got mine today and I love it so far!!
I got mine. Looks like 2 legs are crushed 
Pink color - holes for legs on the mcpcb.
Does anyone else have this problem?
Edit:
This post shows the cause - there are screws in wrong holes. Just like E07 
Edit 2: prototype version looks OK
My first of two arrived … I love it. Installed my Towild silicone diffuser and instantly turned my new TO50R into a lantern. The Towild diffuser is a perfect fit. I am super pleased with all aspects of this setup. Acebeam 21700 5100mAh batteries are a perfect fit as well … 
Lantern Link:
Mine is also broken
Mine also - guess they all have broken legs
Have not received mine yet. Tracking shows the package has not moved since 12 days. Last time I saw that, the package was sent back to China because of li-ion battery and tracking will not show you that. I wrote to Jason from Wuben 2 days ago to check if they did not received it back but I never had any answer…
These legs are specially broken to screw mcpcb into the flashlight. It’s the same in D4. Look again at my comparison picture:
The screws are in good holes. These next to don’t coincide with the holes in the flashlight.
The prototype had no screwed mcpcb.
I also think that all four legs should be untouched, and screws in places intended for this purpose.
But what will you do …? ¯\/¯
I would say that is because they drilled the holes in the wrong place. The mpcb looks perfectly fitted for screws in the adjacent hole with enough space to fit the optic in without issue. Someone, somewhere along the line screwed up and they used a patch job to fix it…
By the way has anyone else’s flashlight come with oil and aluminum shavings in the top threads? I had aluminum shavings underneath the o ring, in the threads, and inside the battery tube that I had to clean out when I got mine. The bezel had machining oil on it as well, inside the three indentations. Also, aren’t the square threads a bit… thin for what you would normally find on a flashlight of this price? It’s a nice flashlight and all, but the build isn’t exactly up to snuff for what it was billed as. The finish quality and attention to detail of my C8F is above that of this flashlight, and I paid significantly less for it. I know we’re mostly paying for the driver, but still…
I disagree, you can clearly see in the photos from straight above that the unused screw holes are further in from the edge of the MCPCB, I can’t imagine them lining up with where the screws are actually mounted.
The finishing issues sound like a bummer though.