... our factory, it is made from Nitrile(NBR), HNBR ,EPDM, Silicone, Fluorine(FKM,FPM), Neoprene(CR),Styrene(SBR) ,CR,ACM, ... has the below reason:Our O rings in high quality,precision size.Our O rings have the excellent performance as per ... Tooling over 2000 setsWorker 150Staff25QC5Main productso rings, gaskets,custom rubber parts.Material Nitrile(NBR), HNBR, EPDM,Silicone, Fluorocarbon, SBR, Neoprene(CR), ...