... , it is made from Nitrile(NBR), HNBR ,EPDM, Silicone, Fluorine(FKM,FPM), Neoprene(CR),Styrene(SBR) ,CR ... C.D) Minimum0.44mm. O ring outer diameter Maximal 530mm2. Color: black, white, yellow, brown, green, blue, transparent, ... gaskets,custom rubber parts.Material Nitrile(NBR), HNBR, EPDM,Silicone, Fluorocarbon, SBR, Neoprene(CR),Butyl(IIR),NR,PU ... feel free contact with us Blue color soft silicone o ring