1.O-ring :copper material 2.Seal gasket,metal gasket 3.passed ISO 9001, ... Ts 16949 4.color,diameter,length according to requ 1.O-ring :copper material2.Seal gasket,metal gasket3.passed ISO 9001,ISO Ts ... requestO-RIing(seal gasket,metal gasket) It is made from copper,used for sealing .we produce different sizes rings and gaskets ...