For use on the small 6v 99mm and larger 12v 108mm Generator/Alternator top pulley
Holds top pulley in place while undoing the 21mm nut that holds the pulley halves together. lightyears easier and better than the ol' screwdriver.
Makes life a lot easier to change or adjust the belt tension . Lightweight tools just tuck away in the vehicle with a replacement belt just incase …..