Edelbrock Part 15035 Tensioner Upgrade Kit is engineered to handle the increased belt stress encountered in high horsepower Edelbrock applications. This kit is an upgrade for part 1572, 1575, 1591 1594 Edelbrock Supercharger Systems produced prior to February 2013 and are now included on all systems thereafter. Kits includes tensioner, tensioner mounting bracket, Gatorback drive belt and hardware.