OTC 4645 Serpentine Belt Tool Fits tensioner pulleys with 13 mm to16 mm 18 mm hex or 3/8" and 1/2" square drives For hard to access tensioners there are 13 mm and 15 mm 12-point wrenches built into the handle Also included are 13 mm 14 mm and 15 mm crows foot wrenches One year limited warranty