The Tunerz Tune-Up Kit will greatly reduce string, limb and bow noise and vibration. The unique design of each Tunerz molded from AccuFlex material improves accuracy and performance with near zero loss of speed and kinetic energy. The kit contains two of each Tunerz-bow, string & speed. Tunerz are soft yet very tough and should last thousands of shots. Custom tuning is possible because Tunerz just snap on - No glue or screws needed. Tunerz can be used on all compounds, crossbows and traditional bows.