Swift Coilover Springs. 65mm Inner Diameter, 152mm (6 inch tall) Free Length, 28kg (1568 lbs) Spring Rate. Sold in Pairs. Made In Japan. Highest Quality Springs on the Market! Maintains the best spring rates under compression. Better Spring Memory and Lighter than other comparable springs. Z65-152-280. Other Spring sizes and rates available upon request. Please call for more information.