DIYers and makers, this Kozelo screw assortment kit is absolutely essential for your workshop! You get 200 pieces total with M4 socket head cap screws in 7 different lengths: 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, and 25mm - plus matching nuts for complete fastening solutions. Made from tough alloy steel with black oxide coating, these screws are seriously durable with a hardness rating of 12.9 that won't deform under pressure. The internal hex design provides even force distribution so you're less likely to strip the heads during installation. Perfect for 3D printers, RC projects, machinery, furniture assembly, electronics, and pretty much any project requiring reliable fasteners. The included wrench makes installation a breeze, and the organized assortment means you'll always have the right size on hand. The black oxide finish looks professional and provides some corrosion resistance for indoor use. Having this comprehensive kit saves you multiple trips to the hardware store and the frustration of not having the right size when you need it. The quality is noticeably better than cheap hardware store screws - these feel substantial and precisely made. Whether you're building, repairing, or creating, having the right fasteners makes all the difference in your project's success and longevity. The socket head design allows for tighter spaces and more torque than traditional screw heads. Your workshop isn't complete without this versatile screw assortment that handles virtually any M4 fastening need you encounter!