They are maintenance free, do not leak air, and do not require airlines or compressors.
SumoSprings are a patented suspension product designed to enhance load carrying ability, stabilize sway, and improve overall driver control and ride comfort. 20-Current Jeep Gladiator JT;Rear;Sold as a pair (left and right);Maintenance-free;Enhances load carrying ability;1400 (lb) Capacity at 50% compression;Reduces and stabilizes sway;Improves overall driver control and ride comfort;Compress up to 80% of original height with full memory rebound;One-piece unit attached on one side used as a replacement/upgrade to factory bump stops;Progressive spring rate with superior damping properties;Made from patented micro-cellular urethane;Will not leak or rupture;Never load any vehicle beyond the manufacturer's GVWR;California Residents: WARNING Superspring SumoSprings Set - SSR-407-40 They are manufactured from proprietary closed micro-cellular urethane providing a smooth and progressive spring rate with superior damping properties. SumoSprings are manufactured in a variety of heights, diameters and densities to support multiple front and rear applications..