The ICON Vehicle Dynamics 2020-UP Ford F-250 & F-350 Super Duty 4.5" coil springs are designed for drivers demanding the ultimate in performance and ride quality, while allowing for increased wheel travel (when used with ICON shocks) and the fitment of larger tires. The ICON Ford Super Duty coil springs provide 4.5" of lift height and feature a dual rate design. The dual rate design allows for a softer initial rate for superb on road comfort and a firmer secondary rate that increases during compression for excellent bottoming resistance and off-road performance. Like all ICON coil springs, they feature a lifetime guarantee against sagging/breakage to produce confidence in knowing that you have the best suspension products available for the 2020-UP Ford F-250 & F-350 Super Duty.