Firestone Coil-Rite Air Helper Spring Kit Front 05-18 Ford F250/F350 (4WD Only) (W237604160)If you're looking for a smoother ride for your vehicle that has a coil spring suspension, Firestone Coil Rite air helper springs are what you need. Designed to fit inside existing coil springs to create a variable spring rate, Coil Rite will level your vehicle and assist with more effective braking and handling, even under heavy loading and adverse road conditions. Coil Rite enables you to control the air pressure in the air helper springs so you can