Lippert 279689 Equa-Flex Suspension Upgrade Kit for Triple Axle 5K - 8K Equa-Flex rubberized equalizers replace standard cast equalizers to provide a more comfortable towing experience by absorbing road shock/vibrations and reducing fore to after trailer movement knows as chucking 5,000-8,000-pound Axle Capacity Triple Axle Configuration Easy bolt-on installation; Trailair by Lippert Components Equa-Flex Suspension Upgrade Mounting hardware included