where to buy plastic Caps for C8 Pills

Hi!
I want to use this C8 copper pill *on a uniquefire T20

But I can’t find the Plastic cap that Holds the LED MCPCB in place

Do you know where to buy it?
Thanks
*

1. It is brass, not copper
2. This cap dont hold mcpcb in place. It helps to avoid reflector short-circuis
3. For zoom light you need black one.

for a reflector light you need a centering ring or gasket matching the reflector hole and the LED size
http://www.kaidomain.com/p/S026984.11mm-x-1mm-White-Plastic-Insulation-Gaskets-5pcs

the reflector pushes the MCPCB down of course you can add 2 threaded holes to hold the MCPCB and prevent it from rotating, which can cut in the wires