The Dayco Serpentine Automatic Belt Tensioner is designed to provide less operating range variation and reduce the risk of premature accessory bearing failure due to high tension. This tensioner features a flat spring design to promote quieter performance and longer life. The tensioner has a counter clockwise direction and a single pulley with a diameter of 74mm and a flat design. This tensioner is the perfect solution for your serpentine belt needs. FleetPride is your First Click in Heavy Duty®.