Material: These drill bits are made from HSS carbide with reinforced head, the durable alloy makes it stable and durable, can prevent the drill bit from cracking, extend the service life, can endure a long time using Specifications: Including 4 drill bits, easy to replace, 121.6mm / 4.8inch total length, 7.5mm / 0.3inch shank diameter, convenient and economical, which can fully meet your needs High efficiency: the flute design, the larger spiral chip space of the multi-functional drill bit make non-stick crumbs, smooth cutting and quick chip removal, the edge enables fast engraving, high working efficiency Quality Drill Bits: Quality triangular handle multi-function drill bits can easily penetrate various materials, easy to locate, stable drilling, fast speed, no damage to boundaries and sharp openings; The handy drill set is a nice gift for your friends who love to DIY Processing range: These punching drills contain sharp and stable carbide tips that can easily penetrate various materials, such as tile, concrete, brick, glass, plastic, wood and more, universal and difficult to break these materials. Cutting diameter (mm): 6mm / 8mm / 10mm / 12mm Note: This does not include other things, the color is based on the first picture, and other pictures only show effect Due to the differences between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement. Please allow deviation. Thank you!