Vehicle Compatibility: This air springs kit fits 2011-2025 Silverado Sierra 2500HD 3500HD; In-Bed Hitch is compatible What's Included: Brackets, air springs, hardware, air line and separate valves for manual inflation, the same as you would use for inflating a tire; everything is included for a quick easy installation Absorbs Road Shock They use two convoluted air springs that can be individually tweaked to accommodate dynamic loads; Inflate or deflate your vehicle's air springs and see how they help enhance your ride by absorbing road vibrations and lessening interleaf friction Prevents Permanent Sagging: Ride-Rite air helper springs stop leaf springs from permanent sagging under constant load and lower your chances of bottoming out by softening contact between the frame and axle Ride Quality: Ride-Rite air springs work to maximize your vehicle's safe load-carrying capacity, stability, ride quality, and brake effectiveness