The range of resilient, pottable elastomers is limited to compounds such as urethane and plastisols and cannot offer the wide range of chemical compatibility afforded by all of the different types of materials available in O-rings such as nitrile, silicone, ethylene propylene diene, polytetrafluoroethylene, neoprene, isoprene, fluorosilicone or perfluoroelastomers, as well as others.