ICON Vehicle Dynamics 2021-2024 Ford F-150 4WD suspension systems are designed with maximum performance and the serious driver in mind. ICON engineers? primary focus is to increase wheel travel and damping ability, which translates into outstanding vehicle control and ride quality both on and off-road. The Stage 4 system includes vehicle-specific tuned 2.5? coilover shocks featuring CDXS equipped remote reservoirs for exceptional cooling properties and ICON-engineered coil springs for superior vehicle ?feel? through the range of travel. These coilovers are also height adjustable from 0-2.75? of lift over stock, allowing the use of larger, more aggressive wheel and tire combinations. ICON 2.5 Aluminum Series CDXS piggyback reservoir rear shocks utilize a vehicle-specific valving that balances the performance of the truck from front to rear. ICON's exclusive Compression Damping Dual Speed (CDXS) valves are included for precisely dialing in your suspension performance. CDXS controls fluid flow under compression, with independent adjustability of high speed and low speed compression force. 10 discreet detented settings for both low and high-speed adjustment knobs allow separate adjustments for handling response and overall aggressiveness. The ICON Vehicle Dynamics 2021-2024 F-150 4WD Stage 4 suspension system is an excellent choice for those drivers looking to enhance the capabilities of their pickup on the road as well as in the dirt.