This Bosch Drill and Screwdriver Bit Set is made from HSS quality steel and includes 35 pieces for various drilling and screw-driving applications. The set features different lengths and types of bits for various screw types and nutsetters for hex screws, along with a magnetic universal holder and a universal holder with a quick-change function. The bits are composed of S2 Modified Steel with an optimized heat treatment process for extra-hard quality and strong performance. All bits are color-coded for quick identification. The set includes HSS drill bits for precise results in wood, featuring a centring tip for accurate hole positioning and a 1/4-inch external hex shank. The set comes in a practical and robust storage box for safe storage and transport. It contains: PH1, PH2, PH3, PZ1, PZ2, PZ3, S 3/4/5/6, HEX 3/4/5/6, TH10, TH15, TH20 (2x), TH25, TH27, TH30, TH40, Nutsetter 6/8/10 mm, HSS 2.0/3.0/4.0/5.0/6.0/8.0 mm, Double blade PH2/PZ2, Double blade Th20/Th25. The drill bits feature cylindrical shank systems suitable for all corded or cordless impact drills. This set is a good choice for universal use.