Product Package content 280 pieces of lock washer1.Utility The lock washer is suitable for quick fixing and repairing, by applying a spring force between the fixing head and the base body to make the washer close to the base body, the bolt thread is close nut or base thread, resulting in increased friction and rotational resistance.2.High quality material Lock washers are made of 65 manganese steel, strong and durable, no deformation, abrasion and corrosion resistance.3.Multiple sizes Quick Lock Washers have 7 sizes most used, M3 M4 M5 M6 M8 M10 M12, you can choose different size according to your need.4.Wide application Fixed washers widely used in machinery equipment, lawn mower, engines, cars, trucks, trailers, toys, bicycles, recreational vehicles, boats, pumps, furniture, etc.5.Economic package 280 pieces of black steel lock washers and a plastic box, each size is separated in a storage box for easy selection and storage. 7 sizes can meet your different needs.