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 and are 100% rebuildable/revalveable. TECH NOTE: Can be installed as secondary shocks in OE location with ICON CDEV coilover conversion part number 61721E. Reservoir Doubler Kit part number 611003 and IIC Alt Function Plug part number 191207 are also required.