Edelbrock Part # 15039 Tensioner Upgrade Kit is engineered to handle the increased belt stress encountered in high horsepower E-Force applications. This kit is an upgrade for part # 1573, #1576, #1592 & #1595 Edelbrock Supercharger systems produced prior to February 2013 and are now included on all systems thereafter. Kits includes tensioner, tensioner mounting bracket and hardware. Drive belt NOT included!