Arnott's Coil Spring Conversion Kit C-2745 for the 2004-2009 Jaguar XJ Series (X350 & X358 Chassis) delivers a seamless and error-free conversion of your Jaguar air suspension system to steel coil springs. The Arnott kit features custom-tuned monotube shock absorbers paired with coil springs made from American steel. The USA designed and assembled kit also includes Arnott's patented (U.S. Pat. No. 9,329,917) Electronic Bypass Module (EBM) to turn off ECATS suspension warning messages.