The 66-1302 Ram 3500 air bag spacer kit is designed for the stock supplemental load capacity air bag set ups. These vehicle come with an auto ride height adjustment for the rear of the truck when pulling or hauling heavy loads. The spacers are designed to fit 1" to 2" rear additional lift heights, mainly for use with our 1-2" rear block kit or our 3/2 or 4.5/2 lift kits. It is made of 1/4" mild steel plate and 1/4" wall mild steel tubing in a 2" deck height. The system on the truck is untouched so that the auto level is not effected by the addition of the blocks and spacers. This allows the added lift heights and keeping the same load capacity of the stock unit. Note: Not for Factory Air Suspension. Factory Air Suspension equipped trucks do not have leaf springs or coil springs. The rear of the vehicle is suspended with airbags only.