ACDelco Gold (Professional) Accessory Drive Belt Pulleys are a high quality alternative to Original Equipment (OE) parts. When the accessory pulleys are rotated due to drive belt motion, they cause the accessory drive belt to activate. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.