Features:Tough, flexible rubber construction,corrosion resistance and strong sealing.Widely use in pipe, valve, hose nut and other plumbing repair or retrofit applications.Can prevent or pipe from leaking and provide positive shut off, stopping the leak saves both and energy.Specification:Material: RubberTemperature range from -22℉to 248℉ (-30 to 120 ℃)Size(mm)=Inner Diameter(ID)*Outer Diameter(OD)*Thickness(T)mmNote: Please allow 0.5-2mm errors due to manual measurementPackage Content:20/30/50(+/-2%)pcs x Flat Washers.