A set of tools for repair and construction necessarily contains such an item as a screwdriver. It is used to unscrew and screw bolts, self-tapping screws and other elements. Of course, to cope with this task can and ordinary screwdrivers that do not have a mechanical device. But increasingly often home and professional masters give preference to cordless electric screwdrivers that perform the same tasks much faster and better. With the help of such a device, the master will easily unscrew or screw in the necessary fasteners.