From the people who brought you Tourna Grip comes the Shock Off 2. This over engineered dampener stops frame and string vibration better than a rubber band. This is the only dampener engineered to stop racket frame and string vibration. Designed with a brass piece in the center of 2 silicone dampeners to absorb more vibration and cancel frame vibration. Does more to eliminate shock and vibration than any other dampener, as all others deal only with string vibration. Great for tennis elbow prevention. One dampener per package.