Kit consists of specific rate front and rear coil springs to improve the launch characteristics of your 1979-04 Mustang (exc. 1999-04 Cobra). An airbag is also included for installation in the right rear coil spring. Fine tuning of air pressure in the airbag will neutralize the axle torque reaction which tends to lift the right rear of the car. Recommended for serious drag racing only, not intended for street use.