Sparco Seat Bases mount to the factory seat mount holes in your vehicle’s floor and provide a flat surface for mounting your SPARCO seat. In order to properly install a seat in your vehicle, you will need one (1) of each of the following, per seat: -Seat Base (either 400 or 500 series) -Hardware Kit (50001) -Track Set (00493) *The Track Set allows for forward and backward adjustment of the seat