Made of durable nylon: light weight, corrosion resistance, good insulation, environmentally friendly materials. Necessary set every day: This assorted round spacer box contains 500 pieces / 8 common sizes, including the most common and most common sizes - M2 M2.5 M3 M4 M5 M6 M8 M10 Practical plastic storage box: Pre-classified for quick identification and protection against loss. Very convenient to use. Intended use: Increase the contact surface of the screw or nut with the surface of the workpiece to prevent the surface of the workpiece from being worn. Multi-purpose sealing ring: Widely used in various fields such as semiconductors, automotive, aerospace, and interior decoration. Mainly for electrical connections, household and commercial appliances, cars, boats, generators, machinery, and systems. Package Contents: M2 Nylon Washer --- 2mmx5mmx1mm (ID X OD X Thickness), 100pcs; M2 Nylon Washer --- 2.5mm x 5mm x 1mm (ID X OD X Thickness), 100pcs; M3 Nylon Washer --- 3mmx6mmx1mm (ID X