The Dayco Tensioner Retainer Pin Set is designed for installation and maintenance of timing belt hydraulic tensioners. Dayco recommends the use of this handy Tensioner Retainer Pin Set to safely retain the hydraulic piston of a timing belt tensioner in a compressed state during servicing. Consisting of 6 different sizes of spring hardened steel pins, the set accommodates a wide variety of timing belt tensioners, including certain serpentine belt applications.