Nomad MN220 Bit Grip

This makes changing strings much easier and safer. The Grip string crank attachment fits on all cordless screwdrivers and, thanks to its profile and soft plastic, it fits snugly against the mechanical knob. There is no play and no rattling here. With its slim shape it works without any problems even with narrow machine heads (such as 12-string guitars). The shaft itself is made of highly stable carbon steel.  The same technology is also used for the Grip Winder string crank.