Firestone Ride-Rite Air Spring Kit 2550 fits rear applications for the 2WD/4WD Ford F-250, F-350 Super Duty. Firestone Air Bags are designed to keep your leaf springs from permanent sagging, reduce bottoming out and reduce tire wear. Firestone Air Bags will keep your load level while improving steering control and braking for an overall improved ride. Firestone convoluted air bags can be adjusted to accommodate your load capacity. Backed by a Firestone Limited Lifetime Warranty.