The Dayco Serpentine Automatic Belt Tensioner is designed to provide reliable and consistent tensioning of serpentine belts. This tensioner features a steel pivot tube on specific designs for enhanced stability, zinc coated mounting bolts that resist rust, and a heavy duty cast aluminum spring case and arm to help resist cracking and fatigue. This tensioner is the perfect choice for reliable and consistent tensioning of serpentine belts. FleetPride is your First Click in Heavy Duty®.