Specifically engineered for the Chevy/GMC 1500/2500/3500 1994 to 2011 with bottom overload springs with 1/2" holes. Engages and disengages in seconds. Has no affect on original ride or handeling when disengaged. It dramatically improves handeling and sway reduction, has anti-rotation key tabs and easily adjusts to match your suspension. Each kit has four StableLoads and is high impact powder-coated. It is backed by our lifetime warranty and has no-drill installation.