1.Compatible Models: GMRCK25D Rear Suspension Enhancement System kits compatible with 2011-2025 Chevrolet Silverado 2500HD 2WD/4WD, 2011-2025 Chevrolet Silverado 3500HD 2WD/4WD， 2011-2025 Silverado 3500HD Cab & Chassis 2WD/4WD, 2011-2025 Sierra 2500HD 2WD/4WD， 2011-2025 Sierra 3500HD 2WD/4WD， 2011-2025 Sierra 3500HD Cab & Chassis 2WD/4WD. 2.Product Features: The rubber springs provide an additional 8600lbs of load support to absorb road shock and improve the vehicle's safe load carrying capacity, ride quality and braking effectiveness. 3.Easy to Install: These rubber springs are the replacements of the bump stop in the original vehicle, no drilling required, no hardware needed, you can install them using basic hand tools. 4.Product Materials: Made of withstand high temperatures and high pressures rubber,the Suspension Rubber Helper Spring Kit has good elasticity to ensure reliability. 5.Note: Please double check and confirm the compatibility of car make and model before purchasing. GMRCK25D Rear Suspension Enhancement System, Compatible With 2011-2020 Chevrolet Silverado and GMC Sierra 2500HD 3500HD 2WD 4WD.The rear suspension system is of hollow rubber spring design. The more weight that presses down on the rubber springs, the harder it is to dent the back end of your vehicle.The rear suspension system can be automatically adjusted to keep the vehicle level at all times.