●304 stainless steel. These washers are made of durable, rust-proof 304 stainless steel. ●5 sizes. This set contains 5 different sizes of washers to meet different requirements. ●Sorted All washers are well packaged and sorted in a plastic box for convenient selection. ●300 pieces. There are a total of 300 pieces of locking washers that you can use for a long time. ●Box packed. All locking washers are well packed in a plastic box in case there is a mess.