High-quality materials: All computer screws are made of high-quality brass, steel, and fiber paper. The nickel and black zinc-plated steel offers excellent rust and oxidation resistance. Variety of types: 228 computer case, power supply, motherboard, hard drive, fan, brass mounting screws, and insulating washers. Sufficient quantity: This set includes 228 screws – a complete and sufficient quantity for your needs. Easy storage: All screws are packaged in plastic boxes for convenient storage and preservation. Widely applicable: Ideal for securely installing PC chassis, power supplies, motherboards, hard drives, fans, and floppy/CD-ROM/DVD-ROM drives. Material: Metal Quantity: 228 pieces Package includes: Motherboard standard copper standoffs (M3 6+6): 24 pieces Motherboard insulating washers (red M3 8): 30 pieces Motherboard mounting screws (M3 5): 30 pieces CD-ROM mounting screws (M3 4): 30 pieces Hard drive screws (M3.5 5): 30 pieces Chassis hand screws (silver M3.5 5): 6 pieces Chassis hand screws (black M3.5 5): 6 pieces High-strength chassis screws (M3.5 6): 24 pieces Standard chassis fan mounting screws (white zinc M5 10): 24 pieces Traditional chassis fan mounting screws (black M5 10): 24 pieces