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 to the base nut or thread, resulting in greater friction and rotational resistance. High quality material：The lock washers are made of 65 manganese steel, sturdy and durable, no deformation, abrasion and corrosion resistance. Various Sizes: Quick Lock Washers have 7 most used sizes, M3 M4 M5 M6 M8 M10 M12, you can choose different sizes by depending on your needs. Wide Application: Fixed Starlock washers widely used in machinery equipment, lawn mower, engines, cars, trucks, trailers, toys, bicycles, RVs, boats, pumps, furniture, etc. Economy 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. Product Description Specification: Material: 65 Manganese Steel Quantity: 280 PCS Size: Lock Washer: M3*9mm, M4*12mm, M5*12mm, M6*14mm, M8*18mm, M10*20mm, M12*25mm Plastic box: 9.5*17*2.2cm Color: black Package includes: 40 x M3 Starlock washers 40 x M4 Starlock washers 40 x M5 Starlock washers 60 x M6 Starlock washers 40 X M8 Starlock washers 40 X M10 Starlock washers 20 X M12 Starlock washers