This Genuine GM Drive Belt Tensioner, part number 12590766, is an authentic OEM product that fits various Buick, Pontiac, Chevrolet, and Oldsmobile models manufactured from 1999 to 2009. It is a direct replacement, ensuring a perfect fit and proper function. This tensioner comes with a 1-year warranty and includes only part reference #2 on the diagram. It replaces part numbers 12564508, 12621651, and 24506508. This tensioner is a crucial component for maintaining the proper tension of your drive belt, ensuring optimal performance of your vehicle.