Improved Handling & Performance: Packed with innovative features, Rancho RS5000X shocks deliver improved overall on-road and off-road handling and performance thanks to Rancho's exclusive Cross Tuned technology Minimizes Rough Ride: Exclusive Progressive Engagement Valving is custom-tuned for each vehicle to help reduce initial impacts at low speeds and minimizes a rough ride Built to Last: The low-friction, self-lubricating seal retains gas and oil for quicker rebound and smoother compression while the application-specific piston delivers heightened control of shock motion due to the expanded piston area Buy with Confidence: Knowing that Rancho RS5000X series shocks are backed by Rancho’s limited lifetime warranty, you can purchase these shocks with confidence Vehicle Compatibility: These Rancho RS5000X shocks are designed to fit 2005-2006 F450/F550 Super Duty with 0” lift Enhance your driving dynamics with Rancho RS5000X series shocks! The Rancho Cross Tuned technology features an exclusive rebound valving system and advanced compression phase, optimizing handling and performance on and off road. Its Exclusive Progressive Engagement Valving is custom-tuned for each vehicle, reducing initial impacts at low speeds and delivering a smoother ride. Equipped with a 16-millimeter nitro-carburized piston rod to resist scuffs and corrosion, double-welded loops at stress areas, and a 35-millimeter sintered iron piston for enhanced structural integrity, it also boasts a polyvinyl protective boot. The large twin-tube body, filled with all-weather fluid, allows for cooler operation, increased vehicle control, and the ability to withstand internal temperatures from -40 to 248 degrees Fahrenheit. A polyurethane rebound bumper and rubber bushings help absorb ride harshness, while the fluon-banded piston enhances responsiveness to changing road conditions for an overall smoother ride. Nitrogen gas pressurized to 150 PSI minimizes air-to-oil mixture, reducing damping performance fade and foaming. The Compression Control Valve is custom-tuned for each vehicle to regulate fluid transfer, absorbing impacts without disc flutter and maintaining shock motion control. The low-friction, self-lubricating seal retains gas and oil for quicker rebound and smoother compression, while the application-specific piston delivers heightened control of shock motion due to the expanded piston area. Backed by Rancho's limited lifetime warranty, you can purchase this shock with confidence. - Vehicle Compatibility: Fits 2005-2006 F450/F550 Super Duty with 0” lift.