Dayco 89318 Automatic Tensioner Assembly 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 patented Deflected Arm Plate dampens arm movement, prolonging the life of the tensioner by limiting the amount of rotational movement The heavy duty cast aluminum spring case resists cracking and fatigue This tensioner is another Dayco product proudly made in the USA Limited Three Year Warranty