Features:Made of copper material, widely applicated for electrical connections on household and commercial appliances, automotive and marine uses in which the power source has a threaded/bolt-type connection.Great replacement for old or broken flat washers. Smooth surface reduces friction between fasteners, preventing isolation, loosening, and distributing pressure evenly.Highly screws, nuts and bolts of same sizes and feature solid bearing surface to prevent nut/bolt head from tearing through material. Specification:Material: CopperSize : M8 x 11mm x 1mm/ 0.32" x 0.43" x 0.04" ( Inner Dia* Outer Dia* Thickness)Package Content:20 x Copper Washers.