ACDelco Gold (Professional) Accessory Drive Belt Tensioner Pulleys are the high quality alternative to Original Equipment (OE) parts. These pulleys are needed to help maintain correct drive belt position and tension. 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.