Dayco® No Slack® Automatic Belt Tensioners are built to outperform and outlast competitive OE parts. This specific Dayco® Automatic Belt Tensioner is manufactured with a specially coated patented flat wire spring to allow the internal tension to be concentric, thus providing a more even degree of constant tension. The heavy duty cast aluminum spring case resists cracking and fatigue. Each component is built to resist rust, endure the toughest of conditions while promoting quieter performance and longer life. Dayco's specially patented Deflected Arm Plate dampens arm movement, prolonging the life of the tensioner by limiting the amount of rotational movement. Another patented feature is Dayco's Nylon Pivot Bushing, which keeps internal components in constant contact to maintain proper tensioner alignment. This tensioner contains a metallic locator pin built to withstand extreme drive demands and properly locate the tensioner for installation.