Cognito air bag kits are built with an upper cross-member & heavy duty lower bracketry to offer strength tieing into both sides of the frame. Air Bag Kits are available for 2001-2010 Chevrolet, GMC 1500HD, 2500, 2500HD, 3500, 3500HD 8lug trucks. Also available is an Electronic height control system for an automatic leveling air bag system. (sold separate)