About this item HIGH QUALITY TO BE TRUSTWORTHY: 304 stainless steel material, Not Rust, anti-moisture, anti - oxidation, corrosion resistant, acid/alkali resistance, high hardness. No pollution, Health lead-free environmental protection non-toxic.MANY SPECIFICATION TO BE CHOSEN: M2 M2.5 M3 M4 M5 M6 M8 M10 M12, total 620 pcs,9 Sizes of essentially the most commonly used Lock washers. PLASTIC HEAT SEAL PACKAGING: Practical and convenient of packing box, All of Lock Washers are packed in a durable and durable box, this box could be use for a storage box. THE WIDE APPLICATIONS: Perfect for electrical connections on household and commercial appliances, car and marine makes use of wherein the power source has a threaded/bolt-type connection.