This SES Suspension Upgrade fits the front suspension of a Nissan Frontier. Each laser-cut piece of steel is precision welded and 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.