Firestone W237604186 Coil-Rite Air Helper Spring Kit with 4" Coil for 2011 GM SUV Mounts inside an existing open coil spring suspension Durable polyurethane air springs Supports 500-1,000 pounds per set Used on pick-ups (front), P-30 Motorhome (front), SUV's and cars Kit includes air springs, air line, fasteners, inflation valves (manual inflation), supports (if required), push-to-connect air fittings and detailed instructions