The 7/8"-14 threaded adapter fittings are compatible with 10AN ORB (O-ring boss) ports. Because the threads on these fittings are not used for sealing, PTFE paste or thread sealant is not required. The FKM O-ring should be lubricated with engine oil. Replacement O-rings are available here.ORB ports are an industry standard and found on many automotive plumbing products, including most Radium products. All fittings include FKM O-rings.