An ACDelco GM Original Equipment Radio Antenna Base is the foundation of your vehicle's antenna, and is a GM-recommended replacement for your vehicle's original component. The radio antenna base performs several functions: provide the antenna cable connection interface, provide the grounding point for the antenna ground plane, and mechanically support the mast and seal out water from the vehicle interior. These original equipment radio antenna bases have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.