Coil spring with a 525 lb spring rate. Made with chrome silicon and has a chrome plated finish. 2-1/2" inner diameter and a 10" length. Available in a chrome plated or silver powder coated finished, QA1's 2.5" I.D. Coil Springs are offered in 6" to 14" free length. QA1's springs are strong, consistent and have a long life because they are made with the highest quality materials. A lifetime guarantee ensures that all QA1 springs will stay within 2% of the original free height and rate under normal operating conditions.