Seal Type Flat Exterior Finish Rustproof Fastener Size M10 Metal Type Copper Number of Pieces 150 Stopper Type Flat See More About This Item Premium Quality: Premium copper rings - Melting point up to 1083°C - Durable and anti-rust flat sealing ring - Good electrical conductivity and thermal conductivity. Features: Copper sealing rings can distribute a load and prevent damage to the surface to be fixed and insulate the steel screws from the surface. A flat washer is used if the hole has a larger diameter than the fixing nut 15 Sizes: M5, M6, M8, M10, M12, M14, M16, M18, M20, M22 - Different sizes of washers in this kit that you can use for different purposes, meet your different needs Easy to Use: 150pcs copper sealing rings assortment, different sizes are placed in different ways, in a compact and comparative plastic case, easy to use and store Wide Application: Copper sealing ring usually used as spacer, wear pad, preloaded display device, locking device to reduce abrasion and