Description: Sierra, silverado. 5.3l. With eassist. Allows for the operation of various pulleys, and drive belt accessories, with the use of a single belt
Creates a secure point of contact with the pulley, which allows for traction
Original equipment parts are designed to work with your GM vehicle safety systems -- aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type

Description: GM Genuine Parts Drive Belt Tensioner Assemblies are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These assemblies are spring-loaded pulleys designed to draw tension on your vehicle's serpentine belt. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. 

Description: Sierra, silverado. 5.3l. Drive belt. Grooved. Helps repair noisy idler pulley bearing This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors Original equipment parts are designed to work with your GM vehicle safety systems -- aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type