Great news… 
Just did a real (non-extrapolated) low mode runtime test on a T3 titanium.
Around 3 days, 16 hours with a 2300mAh energizer japan nimh.
Two runs, two cells of same type, same result.
Was hoping it would be higher, but the low mode isn’t exactly a moonlight mode. Low mode on these is just usable with adjusted eyes hiking on-trail, so 88 hours is at least practically acceptable. Convoy 21700 lights have me spoiled with their several continuous weeks of low runtime.
In the 4-level mode, the second level — “10%” — got exactly 12 hours, so obviously I was hoping for 5 days exactly from “1%” level. I don’t think these current ratings are expected to be very high precision, though.
Received S16 B35AM. The flashlight is excellent, the only thing missing is USB charging. But I was very upset by two large scratches on the glass and a scratch on the reflector.
https://drive.google.com/file/d/1FGfOMVF4lvFFhFRgis4f0DQ9HHxbY92m/view?usp=drivesdk
https://drive.google.com/file/d/1EmxDjrnrkA4U7md8zUE5ivZ94HN-WqhO/view?usp=drivesdk
https://drive.google.com/file/d/1EoHSssVBkR53nKIWSjtPW-GzJBZM2M8Z/view?usp=drivesdk
https://drive.google.com/file/d/1DtcbAgh98P8tsDDNjqdBiZ1uMqQMlyIk/view?usp=drivesdk
Contact Simon on Aliexpress, I would think he would take care of it.
MAO M21B is available now.
Simon can you make a link to bundle it with the battery too?
Will you please make the 2700k and 5700k B35am available for purchase in the S21a? Right now, we can just buy it with 4500k.
What does “MAO” stand for?
Simons Name?
Micro Arc Oxidation
@id30209 Niice.
Getting an M21B MAO right now.
Well, getting it customized with all the stuff that I want of course 
What are the mods, and modded by who?
I’m seriously thinking about settling with the M21B MAO, but I would like the XHP70.3 HI.
I second this. Need M21B Mao with XHP 70.3.
Simon please make this happen. I’m ready to place the order now but need to make sure I can get xhp70.3.
I have several other lights in cart ready to go too.
T4 Ti with 519a 5700k
May grab a Mao T4 too.
And an M21F with 70.3 if available.
I took some time off this hobby but am ready to jump back in.
Edit: dang Mao S21+ too. I might switch the T4 to ti then add s21+. MAO on the tall T4 seems to get dirty quick. It looks beautiful though.
By customized, I meant with the orange lighted switch and my own BeCu springs.
Nothing really special honestly.
Simon, do you plan to produce MAO S21E?
Another question: I like S6, will you install 5A driver for Nichia 519a in it?
Simon, do you still offer M21B MAO with FC40 1800K? I wanted to order it today but some LED options are unavailable. 
P.S. Do you still offer a BLF discount coupon code that I can use during checkout? I remember there once was a publicly available code. Thank you.
For me, all LED options are avaliable, but you have to remove the stuff behind the “?” on the AE link in the post here or go to the product page directly from Simons AE store.
The BLF code isn’t working atm because AE has some new coupon regulations, but feel free to correct me.
I thought you were going with a different emitter and driver perhaps.
S21D please!! I really want a different color.
If I want to buy a MAO M21B with a lighted switch, do I just leave a message to get it or do I need to pay extra via some other way?
https://www.aliexpress.com/item/3256802202717775.html?spm=a2g0o.order_list.0.0.21ef1802sfzhJj&gatewayAdapt=4itemAdapt
(Metal button + adapter + 20mm lighted switch) kit for for M21A M21B M21C M26C L21A S12 S16 etc.
When the battery is fully charged and the voltage is 4.2V
Blue light consumption current 9.4mA,
Orange light consumption current 14mA,
When the battery is low and the voltage is 3.0V
Blue light consumption current 2.74mA,
Orange light consumption current 6.8mA,
Hi Simon if I understand the above correctly, I think there might be an error in the specs you list for the metal button with lighted switch. The numbers listed are way too high and about 10x what is typically seen in my other lights (Sofirn, Wurkkos, Emisar, etc.), which draw about 1 mA for lighted switch.
The consumption caused by that very high 9.4 mA draw would be 9.4mA * 7 days/week * 24 hours/day = 1579 mAh per week, ~1/3 of battery capacity.
This is of course not what I observe so I finally got around to measure the current draw of the lighted switch in both my M21B and S21D. The measured draws are much less (much better) than listed specs: about
0.4 mA for S21D, and
0.5 mA for M21B.
