High quality: All products are made of durable nylon and are corrosion and wear resistant. With washers to increase the contact area, reduce pressure and protect parts and screws. Perfect for electrical connections on household and commercial appliances, automotive and marine applications. Pre-classified for quick identification and protection against loss. Very convenient to use. Easy to install and durable to use, 8 popular sizes, including the most common and frequently used sizes - M2 M2.5 M3 M4 M5 M6 M8 M10, various sizes, for everything you need. Product Description 8 different sizes with 520 pieces. Specifications: Transparent box. (ID x OD x Thickness) M2 --- 2 mm x 5 mm x 1 mm = 100 pieces M2.5 --- 2.5 mm x 5 mm x 1 mm = 100 pieces M3 --- 6 mm x 3 mm x 1 mm = 100 pieces M4 --- 8 mm x 4 mm x 1 mm = 50 pieces M5 --- 10 mm x 5 mm x 1 mm = 50 pieces M6 --- 12 mm x 6 mm x 1.2 mm = 50 pieces M8 --- 16 mm x 8 mm x 1.4 mm = 50 pieces M10 --- 20 mm x 10 mm x 1 mm = 20 pieces