The Rock Krawler X Factor Pro 4.0-inch suspension system with billet aluminum arms for 2011–2016 Ford F-250 and F-350 4x4 trucks pairs a 4.0-inch kit with upgraded billet arms. The description frames the package as a matched suspension upgrade including component boxes and installation hardware for those model years and four-wheel-drive layouts.
Rock Krawler 11-16 Ford F250/F350 4x4 4.0in X Factor Pro System w/ Billet Aluminum Arms