TeraFlex JK: Alpine IR Control Arms provide complete alignment adjustability for maximum performance on JK Wrangler/Unlimited models with 2-4 lifts. Uses factory control arm brackets. Includes our innovative IR (Independent Rotation) Bushings. Can be added to any existing suspension lift. Kit Includes:- One (1) pair of adjustable control arms Balance caster angle and pinion angle Optimize rear pinion angle and tune anti-squat geometry Constructed from durable 42mm x 4mm wall DOM tube for maximum strength Bolts to factory control arm mounting locations Estimated installation time: 2 hours Control Arm Specs:- Tube diameter & wall: 1-5/8″ x 0.175″ (42 mm x 4mm)- Factory length: 17-7/16″- Min. length: 17-5/8″- Max. length: 18-7/8″- Bolt ends: 9/16″ (14mm) bolt- Thread: 1-1/4″-12 UNF Notes:** Alignment is required Fits:Jeep Wrangler JK 2 Door (2007-2018)Jeep Wrangler JK 4 Door Unlimited (2007-2018)