Felo-Smart Engineer Set M-Tec combines the Spring Loaded Nut Driver and the screwdriver and T-handle in one. The magnet body is retractable to allow the nutdriver to take long threaded bolts. A spring-loaded magnet corpus holds the screw or nut and places it also at points which are hard to reach. 20 Pcs in StrongBox. One-hand operation: It´s not longer neccessary to replug the blade in order to switch between screwdriver and T- handle use. All pieces in 1/4" suitable for Cordless Screwdrivers. 2 component handle with soft grip material for highest torque. Blades made from high-quality steels. Anti-roll handle design.