HIGH QUALITY MATERIAL: Hex socket head cap screw bolt and nut kit is made of high quality steel, upgraded version, anti-rust for time. It is characterized by strength, good corrosion resistance in harsh environments such as high temperature, cold and humid areas, excellent rust resistance and toughness can long-term use. [Screw Combo]M2, M3, M5 matching nuts, flat washers, spring washers are included to prevent the bolts from loosening. According to the standard metric system, nuts and flat washers enlarge the contact area and reduce pressure to protect screws and components, and the compact and strong uniform thread is not easy to deform and off during rolling and installation. Exquisite storage box: All screws and nuts are packed in a strong and durable box, which can effectively bear the weight of the whole package. In order to avoid the screws from being scattered or lost during use, we specially package different types of screws for convenience and storage, not only providing you with high-quality products, but also providing them with the best storage system. [Wide Application] M2, M3, , M5 hex head screw washer and nut kits are widely used. Such as precision machinery, instruments, electronic products, household appliances, communication products, locks, , toys, etc. Suitable for , landlords, repairmen, other DIYers. This set is perfect for replacing broken and missing screws, it's your perfect when you're crazy about missing bolts, this set comes in many different sizes to fit your biggest requirements. Note: due to different production batches, the plastic box style is random, Cannot be chosen the specific style Material:steel colour:black Package Contents: 1 x 2000pcs Screw nut kit (M2 (20mm 16mm 12mm 8mm each 40pcs screw. nut, spring, spring washer 160pcs each) M3 (20mm 16mm 12mm8mm each 35pcs screw. nut, spring, spring washer each 140pcs) (20mm 16mm 12mm 8mm each 30pcs screw. nut, spring, spring washer each 120pcs) M5 (20mm 16mm 12mm 8mm each 20pcs screw. nut, spring, spring washer each 80pcs) ) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.