Premium Material: Computer replacement screws are made of high-quality carbon steel, oxidative blackening. These small screws are sturdy for long time use. Sizes & Quantity: 520Pcs computer screws. 26 sizes PC screws, 20Pcs of each size(mm) : M1.4x 4, M1.4x6, M1.4x8, M1.7x4, M1.7x5, M1.7x6, M1.7x8, M2x4, M2x6, M2x8, M2x10, M2.5x4, M2.5x5, M2.5x6, M2.5x8, M2.5x10, M2.5x12, M3x4, M3x6, M3x8, M3x10, M3x12, M3x14, M3x16, M3.5x5,M3.5x6. Sufficient quantity and sizes for daily use and installation need. Wide Application: These micro screws are perfect for most types of computer, laptop,notebook, such as DELL,Sony, IBM, HP, Toshiba,Samsung,Acer,Asus,Lenovo. The screw assortment kit is also suitable for SSD M.2, SATA, motherboard, fan, hard drives fixed installation. Plastic Storage Box: The computer screws are packaged in a plastic box. The mark label on the lid will tell you the size of screws, ensuring a quick search for different sizes of screws. Note: Because the screws are tiny small item, please keep kids,children and pets away from these small screws.