Streetdamprs deliver outstanding control of crankshaft torsional vibration by using race-proven technology. By installing a Streetdampr viscous damper you will reduce wear on the main bearings and timing gear, achieve more accurate valvetrain operation and lower the risk of crank failure. Unlike rubber based dampers, Streetdampr automatically adapts to your modifications, then continuously self-tunes in real time to optimum damping at both peak levels and across a broad, changing frequency range. These dampers are made from steel and feature a natural finish. Not SFI-approved. Made In The USA.