1) EPDM Food grade 2) EPDM Backed by PTFE (Bonded) 3) EPDM Backed by PTFE (Padded) 4) Re-enforced SILICON 5) VITON (on request will be available) As standard procedure we provide lab test certificate for every batch of Diaphragm All our diaphragms come with molded calendar indicating batch number of Diaphragms.