CR rubber o ring 1.Material CR 2.Good tensility, ... X ring,U ring,V ring,O ring,etc CR Rubber o ring 1. Main materialNeoprene(CR),also can use ... Natural rubber, SBR, NBR, IIR, PU, EPDM, Silicone, FKM, FVMQ, HNBR, ... know the use).Hardness or duro.Tolerence.Color.QuantityMORE Rubber ringhttp://www.shanrong-rubber.cn/productgrouplist-212134849/Rubber_ring.html