The Rock Krawler JT 3" X Factor Mid Arm System was specifically designed for those who want a complete bolt-in installation, maximum articulation from a mid-arm kit and the durability and off-road performance you expect from Rock Krawler Suspension. The X Factor Series adjustable lower control arms offer a total of 90 degrees of misalignment. Rock Krawler’s industry leading triple rate coils give you 3"es of lift and improves the on-road ride over the factory linear rate springs. All Rock Krawler JT systems includes two rear spring seats, as well as the corresponding two front spring pads. The provided track bar geometry corrections, both front and rear, lets you perfectly center the axles so there is no compromise in on-road handling.Tire Fitment:Sport and Sahara with Full OEM Fenders37” Tall Tires (3” Bump Stop Height Recommended)Sport and Sahara with Trimmed or High Lined OEM Fenders38” Tall Tires (3” Bump Stop Height Recommended)Rubicon with Full OEM Fenders37”/38” Tall Tires (3” Bump Stop Height Recommended)Rubicon with Trimmed or High Lined OEM Fenders40” Tall Tires (3” Bump Stop Height Recommended)Wheel Fitment:Sport and Sahara Wheel Fitment Recommendations37”/38” Tall Tires - Recommend 3.5” of backspacingRubicon Fitment Recommendations35" Tall Tires - Recommend 4.5" of backspacing37” Tall Tires - Recommend 4.5” of backspacing40” Tall Tires - Recommend 3.5” of backspacingShock Notes:Generic Front Shock Length – 17.8” Collapsed/ 29.3” Maximum ExtendedGeneric Rear Shock Length – 17” Collapsed/ 29” Maximum ExtendedGeneral Notes:*All lift heights based on Rubicon models