The 2011-2019 GM 2500HD/3500HD requires significant shock damping to comply with the massive spring rate of the factory torsion bar system. ICON Vehicle Dynamics has developed a range of suspension systems with optimized vehicle specific shock damping. These systems offer excellent on and off-road driveability. While driving the construction site or trails to your favorite dirt bike location, ICON wants you to get there in comfort just like your drive to work. The Stage 3 system is comprised of our V.S. 2.5 Aluminum Series front & rear reservoir shocks featuring ICON's Compression Damping Control Valve (CDCV) for 10 settings of adjustability for any driving style or condition. The ICON vehicle specific tuned 2.5" diameter shocks with CDCV are the key to attaining optimum ride quality and getting that desired comfort with the 3/4 & 1 ton working capability. Adjustable reservoir shocks ensure optimum performance by increasing the duration of consistent damping regardless of situation, keeping the shocks at a cooler operating temperature during heavy use. Additionally, ICON upper control arms add strength, durability, and when paired with extended travel shocks increases wheel travel 2" over the OEM configuration.