Wide Application - Essential washer assortment kit for home, auto shop and hardware store, meeting different usage requirements. Function - Used with nuts and bolts and provides larger bearing surface to prevent the head of the nut or bolt from tearing the fastened material. Copper material - Strong wear resistance and anti-corrosion, hardness, high conductivity, sturdy and durable. 12 flat washers assorted size - M5M6M8M10M12M14M16 M20, contains a total of 280 different washers for endless use. Please check the detailed dimensions of this item in our photos before purchasing, this set of flat washers with storage box will help reduce pressure and friction when using for your work, convenient to carry and use. Tired of running to the hardware store to find the right size washers The anti-crush washer kit is the best solution for you! Features: Complete sizes of flat sealing washers for all your home DIY needs; Contains a total of 280 different washers for endless use. > Good