The CargoGlide 1500HD is made of a sturdy powder coated steel frame. It has extension of up to 70%, and comes preassembled for easy installation. Comes with 3" side rails and 8" side rails are optional. Has 6 bearings and side rollers to easily slide out the 1500 lbs of payload.  The CargoGlide 1500HD has been tested to 50% over its stated rating, and is available for most full size trucks and vans.