Description: Silverado, sierra. 6.6l. Dual alternators. 6.6L diesel, with dual alternator, 150/150 amp. 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