https://www.junmaseal.com/products/fkm-gasket-material-301-304.html FKM Gasket Material (301/304) FKM rubber gasket are derived from a synthetic fluoroelastome. It provides excellent resistance to Chemicals, Petrol and oils. It commonly used in the automotive, oil sectors and aerospace. It has excellent thermal stability. The temperature wil be -20°C up to +205°C.