The product is an original equipment manufacturer (OEM) used AC idler pulley for a 1965-66 Ford Mustang. This vintage part is specific to Ford vehicles and is not universally fitting. It is not a performance part, but rather a genuine replacement part for the specified year and model of the Ford Mustang. This idler pulley helps to ensure proper functionality of the AC system in the vehicle, making it a crucial component for maintaining the overall performance and longevity of the car.