Yep, I know about it but didn't find out until last week when I was checking the condition of the red o-rings on my ProVari mods ... AND ... didn't find any red o-rings on the 2.5 and mini !!!
I've not had to replace a red o-ring yet but have a couple of spares just in case ...
![]()
And a helpful hint I got from Brandy at Provape (when there was a Provape) ... was to insert the tips of a small pair of needle nose pliers into the o-ring. Then open the pliers to spread open the inner diameter of the o-ring and then carefully slip it over the 510 pin. Worked like a charm when I had to replace one.

