Threaded Anti-Vibration InsertsReduce Vibration While Securely Mounting Hand Guards. Threaded Anti Vibration Inserts absorb vibration while securing your hand guard by tapping the end of the handlebar and threading the Insert into place. The result is a solid hand guard anchor that minimizes vibration. An incredibly effective component for any serious racer or casual rider, our inserts absorb the vibration transferred from the bars to your hand yielding less fatigue and arm pump.