... one of the main products in our factory, it is made from Nitrile(NBR), HNBR ,EPDM, Silicone, Fluorine(FKM,FPM), Neoprene ... AS568,Metric, GB 245201.O ring detail for reference:1. Size : O ring circle diameter (C.D) Minimum0.44mm. O ring ... etc.Rubber moulding over 2000 setsWorker 150Staff25QC5Main productso rings, gaskets,custom rubber parts.Material Nitrile(NBR), HNBR, EPDM,Silicone, Fluorocarbon, SBR ...