these gaskets are made from 'v' shape metal strip of ss 304/304l/316/316l and with filler material caf, grafoil, ptfe along with guide ring of ss 304/304l/316/316l & carbon steel as original. We also offer the material without inner & outer ring of ss/cs as per customer requirement. these gaskets are available in sizes of 1/4" to 60" according to api 601,api 605, bs 3381, bs 4504 & bs 3293, ansi 16.2/16.5 standards in round, square & oval shapes