This steel spacer can be widely used in high-temperature, high-pressure, and highly corrosive pressure, valves, sealing parts of cylinder heads, and industries such as car, steel mills, chemical equipment, and engineering machinery.Specification Material: Carbon SteelSize: 12.3mm ID x 20mm OD x 15mm L/ 0.48inch ID x 0.79inch OD x 0.59inch LAdvantageMade of durable Carbon Steel 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.