Sizes and components - M2 x 8/12/16/20 mm, M3 x 8/12/16/20 mm, M4 x 8/12/16/20 mm, M5 x 8/12/16/20 mm screws with matching hex nuts and flat washers. Different sizes meet a range of mounting needs. Material and durability - Made from 304 stainless steel, offering good corrosion resistance in challenging environments such as high temperature, cold conditions, and high humidity. Provides rust resistance and excellent oxidation resistance for long-term use. Packaging and convenience - 1280 pieces in total, packed in a durable transparent box with labels. Easy size identification helps you grab the right screw without extra shopping, covering all your fastening needs. Wide applications - Widely used in precision machinery, instruments, electronic products, printed projects, household appliances, communication products, locks, lamps, lights, toys, and more. Use scenarios - Electronics and enclosures: mounting PCBs and assembling electronic devices or instrument housings. - Home and workshop repairs: fixing components in household appliances, lamps, locks, and furniture. - DIY and prototyping: hobby electronics, robotics, model projects, and small-scale prototypes requiring reliable fasteners.