Country of Manufacture: CHINA; Material: RubberFeatures: 3mm inner diameter, 8mm outer diameter, 2mm thickness.Package Content: 30 x Flat WasherCorrosion Resistant w/ Reduce Galling.Application: Widely used in chemical industry, bicycle or motor production.1.Tough, flexible rubber construction, high temperature resistance, corrosion resistance and strong sealing.2.Replacing the washers will create a better seal and help prevent leaks for the future.3.Intended for use in, pipe, valve, hose nut and other plumbing repair or retrofit applications.4.Can prevent or pipe from leaking and provide positive shut off, stopping the leak saves both and energy.