Made of high-quality S2 steel, with sturdy hardened & tempered construction, Perfectly matched to most standard tamper-resistant German-made star 6-point screws. This set includes 11pc 1/4-inch shank tamper resistant star bits Tamper Resistant sizes are: T-7, T-8, T-9, T-10, T-15, T-20, T-25, T-27, T-30,T-35,T-40(2 Inches). Used in automobiles, repairs, trucks, automobiles, engines, motorcycles, interiors, dashboards, computers, cable boxes, toys, appliances and consumer electronics, drill bits can also be used in many other protected parts. Designed to prevent Cam-Out the 6-Lobe 1/4" shank hex bits clicks onto most standard sockets, screwdrivers, drill/driver kits & Power tools attachments. The hole in the center in each bit causes it to be tamper resistance.