1. Quality certificate: ROHS. 2. Materials: NBR, NR, FPM...etc 3. Use for all machines,size:50-630 O RING1.Product/Service(We Sell): O-rings,U-type loops,Y-type loops,customized rubber items2.Material NR, SI, EPDM, NBR, SBR, FPM, IR,, BR, IIR, PU, etc, just as your request.3.Certification: ISO 9001:2000; SGS,PAHS,LFGB,ROHS,FDA,etc4.Size: customized5. Color: all available6.package: 5000 pcs/bag, ...