Liftcraft - 2011-2018 Silverado Sierra Leveling Kit 2500HD 3500HD Adjustable 1 to 3 Inch Front Torsion Bar Lift Keys and Shock Extenders plus Unloading Tool 4WD LIFT: 1-3 inch adjustable front suspension lift over stock FITMENT: 2011 - 2018 Chevrolet Silverado 2500HD, 2011 - 2018 Chevrolet Silverado 3500HD, 2011 - 2018 GMC Sierra 2500HD and 2011 - 2018 GMC Sierra 3500HD Models | NOTE: Will only work on 8-lug models; 4WD Only MATERIAL: Made of High Strength Steel, two times the strength of your factory keys INSTALLATION: Bolt-on kit, only takes a couple of hours to install; No modifications required CONTENTS: Carbon Steel Torsion Keys (2), Carbon Steel Shock Extenders (2), Torsion Unloading Tool (1) and Detailed Instructions - Liftcraft suspension lift and leveling kits come with a lifetime guarantee and are the easiest, safest, and most affordable way to improve the look of your truck and run bigger tires