Made of durable nylon: Lightweight, corrosion-resistant, good insulation, and environmentally friendly material. Intended for general use: Increases the contact area between the bolt or nut and the surface of the part to prevent wear. Daily essential: This box of assorted round sp washers contains 500 pieces in 8 popular sizes, including the most common sizes—M2, M2.5, M3, M4, M5, M6, M8, and M10. Convenient plastic storage box: Pre-sorted for quick identification and protection against loss. Easy and convenient to use. Widely used in various fields such as semiconductor, automotive, aerospace, and interior decoration. Commonly used in electrical connections, household and commercial appliances, automotive, marine, generators, machinery, and equipment. Package includes: M2 Nylon Flat Washer – 2mm x 5mm x 1mm (ID x OD x thickness), 100 pcs; M2.5 Nylon Flat Washer – 2.5mm x 5mm x 1mm (ID x OD x thickness), 100 pcs; M3 Nylon Flat Washer – 3mm x 6mm x 1mm (ID x OD x thickness), 100 pcs; M4 Nylon Flat Washer – 4mm x 8mm x 1mm (ID x OD x thickness), 50 pcs; M5 Nylon Flat Washer – 5mm x 10mm x 1mm (ID x OD x thickness), 50 pcs; M6 Nylon Flat Washer – 6mm x 12mm x 1.2mm (ID x OD x thickness), 50 pcs; M8 Nylon Flat Washer – 8mm x 16mm x 1.4mm (ID x OD x thickness), 40 pcs; M10 Nylon Flat Washer – 10mm x 20mm x 2mm (ID x OD x thickness), 10 pcs.