ACDelco Gold (Professional) Heavy Duty Serpentine Belts are a high quality alternative to Original Equipment (OE) parts. Serpentine belts are multi- ribbed, and used to drive multiple devices on an engine such as the alternator, the power steering pump, and the water pump. 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.