This Aluminum spacer can be widely used in high-temperature, high-pressure, and highly corrosive pressure, valves, sealing parts of cylinder heads, and industries such as steel mills, chemical equipment, and engineering machinery. Specification Color: SilverMaterial: AluminumFit Screw Bolts Size: M5Size: 5.2 x 10 x 10 mm / 0.2 x 0.39 x 0.39 inch (ID*OD*L)Packing List: 20 x Round Aluminum SpacerAdvantageMade of durable Aluminum material, which is hard, good performance, good electrical conductivity, corrosion resistance and can be used for a long time.Instruction Easy to use, just need to install on the screw bolts with proper diameter.NOTE: Please select the appropriate size according to your needs.