This SES Suspension Upgrade fits the front suspension of a Chevrolet Silverado 1500/2500/3500 & GMC Sierra 1500/2500/3500 truck (see below for full list of applications). Each laser-cut piece of steel is powder-coated to ensure a quality fit. 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 (weight from a snowplow or heavy aftermarket accessories - such as a steel bumper) the harder they work to prevent front-end sag. This product ships in approximately 1 days