Coil spring with a 500 lb spring rate. Made with chrome silicon and has a chrome plated finish. 2-1/2" inner diameter and a 8" length. QA1's 2.5" I.D. Coil Springs are offered in 6" to 14" free length and available in a chrome plated or silver powder coated finish. QA1's springs are made with the highest quality materials to make them strong, consistent and have a long life. A lifetime guarantee ensures that all QA1 springs will stay within 2% of the original free height and rate under normal operating conditions.