... high quality NBR/FPM/Viton2.application:for car or motorcyle ,valve stem,machinery and so on3.with excellent heat-resistance and ... Improved oil resistance 4.we are manufacturers ,having various valve stem seals in stocking5.having our own factory,we can ... Stem Oil Seal for Heavy Truck Applicationauto,motorcycle, machinery, water pumps, valves, etc. MaterialVITON,FPM,NBR, SILICONE, HNBR, CR, PTFE, ...