Supply kinds of hardware kits such as copper washer, hitch pin, cotter pin spring, e-clip, woodruf keys, nuts, screw, grease and so on.offer a wide range of O-ring in all standard size and a lot of special size. 2. All o-ring are made according to international standard: ISO 3601, AS 568A, DIN3771, JIS B2401;Material: NBR/Silicone/Viton/HNBR/EPDE/CR/PTFE/PU/ACR/SBR Size: Metric/inch 225pc o-ring kit, 382pc o-ring kit, 386pc o-ring kit, 404pc O-ring kit, 407pc, 419pc o-ring kit, etc