The Rock Krawler X Factor X2 Pro kit component boxes reference the long-arm system with a 6-inch rear stretch for 2007–2018 Jeep Wrangler JK 2-door applications and a 4.5-inch base lift. These component boxes are associated with the X2 Pro long-arm architecture and the extended rear stretch configuration specified for the listed Wrangler two-door years.
Rock Krawler 07-18 Jeep Wrangler JK 2DR 4.5in X Factor X2 Pro Long Arm w/ 6in Rear Stretch