Swift Coilover Springs. 65mm Inner Diameter, 228mm (8 inch tall) Free Length, 5kg (280 lbs) Spring Rate. Sold in Pairs. #Z65-228-050. 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. #Z65-228-050. Other Spring sizes and rates available upon request. Please call for more information.