Speedwinder, fast one.

HB Speedwinder is an useful gadget, and helps me a lot when changing strings, either on my basses, or on guitars. It's head is cut to fit any standard winders.

To use it effectively, one should have the instruments fixed firmly, otherwise the Speedwinder might slip off the winder.

I give it four stars due to the fact that it is a bit hard to separate head from handle, when using it in a power drill for even faster unwinding of the strings.