High Quality CopperSolid copper with high conductivity, heat resistant, high voltage resistant. They are very suitable for sump plugs, water, fuel and hydraulic accessories.ApplicationCopper discs are perfect for electrical connections such as household, commercial equipment, automotive, ships, generators, mechanical engineering and factories.FunctionThe flat washers can distribute the load evenly, prevent damage to the attached surface and insulate the steel screws from the surface. This reduces friction to prevent the spread of pressure or pressure distribution.Dimensions and quantity: the copper seal set contains 200 pieces / 9 sizes (M5 M6 M8 M10 M12 M14) most commonly used copper discs.Perfect storage box: the O-ring copper discs are neatly packed in a plastic box for easy storage and carrying. M5 * 9 * 1 30pcs M6 * 10 * 1 30pcs M6 * 12 * 1 20pcs M8 * 12 * 1 20pcs M8 * 14 * 1 20pcs M10 * 14 * 1 20pcs M12 * 16 * 1 20pcs M12 * 18 * 1.5 20pcs M14 * 18 * 1 20pcs