Air Lift Introduces LoadLifter 5000 For 2011-2015 Chevrolet And GMC 3500 Trucks - GM Authority (blog)

To effectively absorb shock, the LoadLifter 5000 Ultimate kit features an internal jounce bumper which compresses in stages. The LoadLifter 5000 kit may be purchased at nearly any truck accessories retailer, and from various online resources. Source: gmauthority.com