Tensioner and Idler Pulley is precision engineered and tested to the industry's highest standard. It maintains correct belt and chain drive tension extends the life of critical drive components and reduces system downtime. This tensioner reduces belt and chain whip on long center drives and resonant frequency of chain drives. Increases drive efficiency. Ensure drive components do not snag obstructions. Maintains correct belt and chain drive tension. Reduces belt and chain whip on long center drives. Extends the life of critical drive components.