Introducing the finest air spring suspension system available today.. Belltech AirJack Suspension Systems are capable of handling heavy loads without sacrificing the quality ride of your existing suspension. The AirJack System features heavy duty Firestone 100 PSI Air Springs and specific fit Air Spring brackets die cut from 1/4-inch steel plates that are MIG welded for maximum strength. The Air System is tied together with high pressure DOT approved Synflex air line secured with Slip-in-Lock Teflon coated brass air line fittings. All AirJack systems are designed for each individual application and are easy to install with simple tools. So if you already own a Sport Truck or plan to build one, insist on AirJack.. Because there's nothing worse than getting stuck with an unexpected load. An optional onboard compressor kit is available.