The Beatrush Super Light Subframe replacement for the Subaru WRX Sedan and STI 02-07 is made from 7075 Aircraft Aluminum that gives a great strength to weigh ratio. It results in a weight savings of 20lbs from the front end of the car. Used to prevent chassis distortion, makes the front end feel more tight and rigid. This is 4 piece kit that includes all necessary hardware required for installation. This product does replace your factory sub frame completely. This kit is only for the sedans and will only work with the Beatrush Anti-Lift Kit.