TeraFlex JK FlexArms can be added to any existing suspension lift. FlexArms allow custom pinion and caster angles to be set for proper alignment, they also are used to re-center the axle in the wheel well for proper suspension movement. Sold in pairs factory length= 20-5/16” min. length= 19-7/8” max length= 22-1/16” Uses 9/16” [14mm] bolt, 1 1/4-12 UNF thread, 1 1/2” wrench on tube, 1 7/8” wrench on Jam nut.