Firestone Ride Rite Ford F250/F350 '11 '16 And F450 '11 '13. They are designed and assembled in the USA. Ride Rite air springs use the same Firestone technology used on many heavy duty trucks trailers and buses on the road today. Ride-Rite air helper springs utilize a pair of convoluted air springs which can be adjusted for changing loads. These air springs are capable of 3200 to 5000 lbs. of load leveling capacity. Ride-Rite air helper springs enhance the ride by reducing inter-leaf friction. Please remember that air springs do not increase the load carrying capacity of your vehicle. Features of Firestone 2597 Ride Rite Ford F250/F350 '11 '16 And F450 '11 '13 Improves steering control and braking effectiveness level headlight beams and reduce tire wear Individual inflation valves allow for side-to-side adjustment Keeps leaf springs from permanent sagging under repeated or constant load Protective air cushion softens contact between the axle and frame and absorbs road shock providing ideal ride conditions for your passengers and load Fits 2011-2013 Ford F250 and F350 2WD and 4WD models along with 2011-2013 F450 2WD and 4WD models Package Contents: Firestone 2597 Ride Rite Ford F250/F350 '11 '16 And F450 '11 '13 Firestone 2597: Ride Rite Ford F250/F350 '11 '16 And F450 '11 '13