CRX, you’re too much! 
Fitting name for the host with QTC 
CRX, what is that black middle section in Quantum mule? I’ve been meaning to ask the same about black knurling on Spy you had shown earlier.
Is QTC abrasion-resistant? I’ve never seen this stuff in person. How long does it last? Would placing some thin cooper foil over it extend its lifetime or will it degrade performance with more conductive area?
Tritium switch idea is just brilliant (lame pun intended 
) - I’m guessing some epoxy prevents it falling out?
I use a graphite/ resin mix or JB weld.
I give a description about it Here
You can see more lights with this if you view my sig picture.
It can compress many times but is weak torsionally so making a sandwich with thin copper sheet is a good idea. Other lights i have used it in i make the pill at the negative end of the battery so there is no twisting on the QTC material.
The tritium vial is epoxied inside a plastic tube. The vial goes through the end of the keyring attachment but the plastic tube butts up against the underside. The hole closer to the light body is larger so the plastic covering slides through it onto the button.
Thanks for the link, CRX. The treatment looks very chic. I also browsed through your other lights collection and I’m very impressed with your lights and finishing ideas. Very inspiring. Thanks for sharing with us :+1:
And as always: we’re looking forward for more