The package includes: 5 drills. Drill bits of different sizes can meet your different needs. Size: 2.88mm, 3.08mm, 3.28mm, 3.58mm, 4.08mm. High quality: Made of high quality alloy steel, with higher precision, higher hardness, faster cutting speed and strong force than ordinary drill bits. Removable and adjustable: use the included hex wrench to remove the screw and adjust the length of the countersunk hole to adjust the drilling length of screws of different lengths. Practical function: the spiral flute with a center drill will quickly discharge the chips from the hole. It can effectively prevent debris retention accumulation and improve drilling efficiency. Wide application: suitable for drilling holes of wooden material, ideal hole punching drill for solid board, particle board , plywood, MDF. Also suitable for plastic, soft metal, fiberboard etc.