S2 High Hardness of Alloy Steel Material Hardness up to HRC60, stronger than CRV material. Don't worry about wearing out after a certain period of use. Screw head material hardness: Hardness: S2>CR-V>General Steel. Multi-functionThe tool set includes 56 screwdriver bits for maintenance of various devices such as iPad, iPhone, tablet , laptop, PC, smartphone, watch, glasses, camera, PS4/Xbox, switches and other electronic devices. Flexible RodIf the screws you need to handle are hidden in the corners, back or on other fronts, the flexible rod can be bent in any direction you want. Ergonomic Push Design There is a PUSS TO OPEN button near the switch. As long as you press on it, a whole series of screw heads will rise up so you can easily grab one. Once removed, push the entire row of screwdriver bits to retract them. Portable56 bits and 4 tools are housed in one small box. Each type of stacking head has a corresponding card position, and the marking is clear and convenient for loading.