Swift Coilover Springs. 65mm Inner Diameter, 228mm (9 inch tall) Free Length, 6kg (336 lbs) Spring Rate. #Z65-228-060. Made In Japan. Sold in Pairs. Highest Quality Springs on the Market! Maintains the best spring rates under compression. Better Spring Memory and Lighter than other comparable springs. #Z65-228-060. Other Spring sizes and rates available upon request. Please call for more information.