A simple adaptor which fits over the shaft of a bench grinder or motor and is held in place by a grub screw. The mop is screwed onto the tapered thread and when the grinder is switched on the mop 'climbs' up the taper, locking itself in place. These adaptors make changing mops for different compounds quick and simple. 1/2" bore available for left or right hand sides of your bench grinder. Always provide adequate guarding.