It is a simple screw thread corrector that simply holds the screw to be repaired with the V-shaped receiving part and the two blades of Ness, tightens it lightly, and turns it in the direction of the arrow.
Since the two blades move up and down, any screw within the applicable range can be used (inch and left and right screws are shared).
There is play in the two blades, and it is automatically applied to screws of any pitch. It is a type that supports 60 degrees of cutting edge. * If it is difficult to turn the screw when turning it, re-screw it. If you force it, the blade of the main body may break.