These are Viton o-rings from Schmidty Racing Suspensions used on Fox Podium 5/8" shaft and 7/8" shaft shocks to go between the steel shock mounting bushings and the shock eyelet bearings. The 7/8" shaft O-Rings fit on Fox Podium 2.5" and 3.0" with 7/8" shafts.Make sure to select the correct option based on your shaft size!!
Compared to the OEM and silicon rings, these o-rings are made from viton which has a higher durometer (tougher) rating as well as higher petroleum resistance. These do not become soft, swell out, and/or tear like the OEM ones do.