This SES Suspension Upgrade fits the rear suspension of a Dodge Ram 2500 pickup truck. We've engineered our hollow rubber springs to deliver a progressive spring rate. In other words, the more weight that pushes down on the rubber springs the harder they work to prevent rear end sag. Whether you're pulling a trailer or carrying a heavy load in the bed of your truck, our hollow rubber springs adjust automatically to keep the vehicle level at all times. This SES Suspension Upgrade replaces the jounce stop on the frame. Its unique design provides superb ride quality - loaded or unloaded. (There should be a 1/2" to 1-1/2" gap between rubber spring and axle to ensure unloaded ride quality.) Unlike other auxiliary spring systems, the SES Suspension Upgrade guarantees the best of both worlds. This product ships in approximately 1 days