... factory, it is made from Nitrile(NBR), HNBR ,EPDM, Silicone, Fluorine(FKM,FPM), Neoprene(CR),Styrene(SBR) ,CR,ACM, ... etc.Application: O ring is widely used in different industries: Auto, Machinery, Electronic, Water facility, Valve accessories, Air-conditioner, ... rings, gaskets,custom rubber parts.Material Nitrile(NBR), HNBR, EPDM,Silicone, Fluorocarbon, SBR, Neoprene(CR),Butyl(IIR),NR,PU etc. ...