Arnott's Coil Spring Conversion Kit C-3417 for the 2010-2018 Jaguar XJ Series (X351 Chassis) delivers a seamless, error free conversion of your Jaguar air suspension system to steel coil springs. The Arnott kit features custom tuned monotube shock paired with coil springs made from American steel. The US designed and assembled kit also includes Arnott's patented (US Pat. No. 9,329,917) Electronic Bypass Module (EBM) to turn off dashboard suspension warning lights.