O rings for Thrunite Catapult V3?

Does anyone know how I might be able to buy the correct o-rings for my Thrunite Catapult V3? Recently, I made a booboo by lubricating the orings/threads with some wack aerosol silicone lubricant, causing the o-rings to expand and peel.

Also, I've noticed on my Catapult that there are spots for double o-rings on one side of the body tube and on one side of the extension tube. My light came constructed with only 1 o-ring on each side where the double o-rings are. It looks like the tube directly under the head piece shown in one of selfbuilt's pictures. The other tube, on the far left, also has only 1 o-ring installed. Should I double up on the o-rings on these areas? Or does it only have 1 o-ring for a purpose?



Thanks in advance guys.

There we go. Picture below:

Take a piece of tube off your light and go to a Lowes or Home Depot and they should have the o ring there that you can put on your tube to see whcih one fits the best.