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 pairsfactory length= 22-1/2min. length= 22-3/4max length= 25Uses 9/16 [14mm] bolt,1 1/4-12 UNF thread,1 1/2 wrench on tube,1 7/8 wrench on Jam nut.