Bought this after hearing someone mention it having a red mode and fairly low.
http://www.manafont.com/product_info.php/integrated-cree-r5-led-and-red-led-memory-dropin-module-42v-p-7327
The red is pretty low, ugly beam but perfect for night navigation.
The xpg is throwy in the smooth reflector.
All in all I love it 
I built a light for a friend using that dropin and he loves it. Forget about any mods or repairs though…
It’s a fun dropin, hopefully it lasts awhile. I like it 
I bought the blue version for myself and it broke really soon. It’s not a normal driver of course and repairs are difficult with leads for both emitters and the custom star board. The red version is awesome for low-light nightime use.
I’m using diffuser for P60 to get different colors, although reducing output but it still can be usable.
Inner diameter +/- 3,05 cm, made from rubber.