... our factory, it is made from Nitrile(NBR), HNBR ,EPDM, Silicone, Fluorine(FKM,FPM), Neoprene(CR),Styrene(SBR) ,CR,ACM,PU ... rings, gaskets,custom rubber parts.Material Nitrile(NBR), HNBR, EPDM,Silicone, Fluorocarbon, SBR, Neoprene(CR),Butyl(IIR),NR,PU etc.Material ... daysMore information Please feel free contact with us Blue color soft silicone o ring