Arnott's coil spring conversion kit C-3697 is engineered to convert the rear air suspension of 2007-2013 BMW X5 (E70) and 2008-2014 BMW X6 (E71) vehicles to a coil spring system. Featuring powder-coated steel springs and top mounts, Arnott's coil springs are designed to provide a smooth ride without welding or modifying the original suspension. This kit also includes Arnott's patented (U.S. Pat. No. 9,329,917) Electronic Bypass Module to turn off suspension warning messages.