... O-ring,NBR O-ring,HNBR O-ring,EPDM O-ring,CR O-ring,FPM O-ring,PU O-ring.Different material of O-rings have different uses.The ... nbr O ... ,oil-proof,abrasion proof and so on.The O-rings are made in different sizes.The smallest size is 0.74*1.02 ...