Unstable loads while towing and hauling don't just make for an uncomfortable ride. Difficult handling, rear sag, and corner sway create dangerous driving conditions for you, your passengers, and other vehicles. Whether you're towing your RV across the country or hauling hay down the highway, the Timbren SES Suspension Enhancement Kit levels your load, making for a safe, controlled ride, so smooth, you might forget you're towing altogether. Aeon rubber springs deliver a progressive spring rate. As load increases, these rubber springs push back harder, eliminating squat, sway, and roll. After installation, the rubber spring will be in contact with the vehicle's frame. This contact won't affect ride quality â meaning you'll still enjoy a comfortable unloaded ride. What makes the Timbren SES Kit different from other suspension enhancement systems? Unlike air bags, this kit requires no post-installation maintenance. And unlike other systems, you can install and haul in under 30 minutes, right from your driveway.• Reduces sag, sway, and roll when towing and hauling• Comfortable ride, loaded or unloaded• DIY installation• Zero post-installation maintenanceSpecsRated Capacity: 8600 lbs. Kit Height without 1/2" Spacer: 7.25"Kit Height with 1/2" Spacer: 7.75"NOTE: Even though you're increasing the spring rate by adding this upgrade, this does not increase the GVWR (Gross Vehicle Weight Rating). Please make sure that the load does not exceed the GVWR set by the manufacturer. What's IncludedTwo patented Aeon SES suspensions (hollow rubber springs)Two 1/2" rubber spacersTwo mounting bracketsAll necessary hardwareFitmentSuspension Support Location: Rear SuspensionKit Type: Standard Kit1970-1998 Ford F350 Cab and Chassis 2WD1970-1998 Ford F350 Cab and Chassis 4WD2005-2016 Ford F350 Super Duty 2WD2005-2016 Ford F350 Super Duty 4WD1999-2004 Ford F350 Super Duty Cab and Chassis 2WD with Snow Plow Prep Package1999-2004 Ford F350 Super Duty Cab and Chassis 2WD without Snow Plow Prep Package1999-2004 Ford F350 Super Duty Cab and Chassis 4WD with Snow Plow Prep Package1999-2004 Ford F350 Super Duty Cab and Chassis 4WD without Snow Plow Prep Package Eliminate squat, sway, and roll to put you back in control of your vehicle Unlike air bags, it requires zero post-installation maintenance Easy do-it-yourself installation | SES Suspension Enhancement System, FR350SDF Rear Kit