... Application:sealing/airproof ring, water seal ring, water valve/hydrovalve 1)Material:Corundum, mullite, corundum alumina, 95%~99% Alumina, Zirconia Ceramics2)Variety: ceramic ring, ceramic cup, ceramic needle ... friendy and good for health4)Application widely used for seal ring, water seal ring, water valve/hydrovalve ceramic sealing part/ airproof ceramic ring