This is a rear shock absorber kit by ACDelco.  This kit can help to maintain ride height with up to 1,100 pounds per pair as well as have adjustable air pressure between 25-200psi, adjustable air pressure to custom tune each individual load weight, super finished chromed piston rod helps to provide anti-corrosion support, more consistent wear surface, proper seal lubrication, and a longer product life.  GM Part #88946654.