ACDelco 504-549 Specialty Rear Air Lift Shock Absorber Can maintain ride height with up to 1,100 lbs (per pair) of additional temporary leveling capacity to help improve vehicle handling and reduce the risk of undercarriage damage* Adjustable air pressure to custom tune each individual load weight The super finished chromed piston rod provides anti-corrosion support, a more consistent wear surface, proper seal lubrication, and longer product life Real-world tested to ensure that the shocks will fit intended vehicles and applications Not to exceed vehicle GVWR (Gross Vehicle Weight Rating). Product does not increase payload.