1997-2002 Ford Expedition (w/rear coil springs) - "Coil-Rite" Air Bag Helper Springs (Rear)

Firestone "Coil-Rite" air bag helper springs are designed to fit inside the existing coil spring suspension creating a variable rate spring. These air bags are made of durable, elastic polyurethane providing years of comfort and stability to your vehicle. "Coil-Rite" air bags enable adjustment for varying loads and road conditions by inflating or deflating the springs. Performance can be altered as easily as inflating a tire. Installed between the frame of the vehicle and the suspension providing load support through the use of air pressure.