Connects rotor to shaft balancer. Used on all Orbital Sanders and Random Orbital Sanders. High Quality Parts Keep Your Tools Running StrongGenuine 3M™ Replacement Abrasive Power Tool Replacement Parts are engineered specifically designed for your 3M™ Abrasive Power Tools. All replacement parts meet the same specifications and design criteria as the original components. You can be assured the replacement parts will fit, form, and function the same as or better than the original part, which will get your power tool back in action.