Swift Coilover Springs. 65mm Inner Diameter, 280mm (11 inch tall) Free Length, 5kg (280 lbs) Spring Rate. #Z65-280-050 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. Z65-280-050. Other Spring sizes and rates available upon request. Please call for more information.