Suspension Air Helper Spring Kit 313-54 for RAM ProMaster 1500|2500|3500 2003-2021 This air helper spring kit is designed to enhance the rear suspension system of RAM ProMaster 1500, 2500, and 3500 models from 2003 to 2021.It helps improve load leveling, reduce sagging under heavy loads, and provide a more stable ride.The kit includes air springs that integrate with the existing suspension to offer adjustable support based on cargo weight.Installation is designed to be straightforward, using existing mounting points without requiring major modifications.This system supports better handling, braking, and overall driving performance when transporting heavy or unevenly distributed loads.