ICON Vehicle Specific (V.S.) 2.5 Aluminum Series shocks are designed and built to give your vehicle outstanding performance off-road and a smooth ride on the street. These shocks are configured specifically for each application in both length and damping tune. Like all ICON'S Shock Absorbers, V.S. 2.5 Aluminum Series shocks are fully rebuildable and re-tunable. For piggyback and specific remote reservoir applications, ICON'S unique use of a 6061-billet aluminum manifold a few inches below the top cap of the shock creates an internal Bump Zone that when used creates an additional 20% of damping force. This additional force helps prevent harsh bottom outs and controls the suspension when compressing at high velocity. The ICON CDE Valve upgrade is included for those desiring an easy way to tune the ride electronically from inside the vehicle. Compression Damping Electronic Valve (CDEV) is an electronically controlled valve that meters the flow of oil to regulate the amount of damping force that is created by the shock when compressed. This infinitely variable valve can react in less than 40ms and has the ability to make extremely precise adjustments for varying terrain. CDEV*s hydraulic circuits are also custom tailored per application to create the highest resolution and dynamic range allowable for each specific vehicle. Powered by ICON Intelligent Control and proprietary ICON mobile app, the system uses information from the onboard G-force sensor and Gyroscope to perform calculations based on algorithms and user-defined settings to predict terrain and adjust shock settings via the CDEV accordingly. ICON VS 2.5 Aluminum Series shocks are designed and built to give your vehicle outstanding performance off-road and a smooth ride on the street. They feature remote reservoirs with CDEV and are 100% rebuildable/revalveable. TECH NOTE: Also requires installation of IIC kit (Part # 53508) and CDEV front coilovers (Part # 58770E or 58775E) ICON 22-23 TUNDRA 0-1.5"/23 SEQUOIA 0-3" REAR 2.5 VS CDEV RR PAIR