TeraFlex JK: Alpine Short Arms provide complete alignment adjustability and dependability for maximum performance on JK Wrangler/Unlimited models with 2-4 Inch Lifts. Bolts to the factory control arm mounting brackets. High-quality, dependable, maintenance-free, factory-style bushings provide excellent NVH damping and ride quality.Can be added to any existing suspension lift.Includes: Alpine Short Arm Pairs: Arm Pair - Front Upper (# 1415520) Arm Pair - Front Lower (# 1415500) Arm Pair - Rear Upper (# 1415560) Arm Pair - Rear Lower (# 1415540) Fitment: JK Wrangler (2-door) JK Wrangler Unlimited (4-door) Specs: Lift Height: 2-4 Inch Control Arm Specs: JK: Alpine Short Arm Pair - Front Upper (# 1415520): Tube Diameter & Wall: 42mm x 4mm Factory Length: 18-3/4 Inch Min. Length: 18-1/2 Inch Max. Length: 19-3/4 Inch Bolt - Both: 12mm Bushing - Axle: OEM Bushing - Frame: 611014 JK: Alpine Short Arm Pair - Front Lower (# 1415500): Tube Diameter & Wall: 42mm x 4mm Factory Length: 22-5/8 Inch Min. Length: 22-3/4 Inch Max. Length: 24 Inch Bolt - Both: 14mm Bushing - Both: 611011 JK: Alpine Short Arm Pair - Rear Upper (# 1415560): Tube Diameter & Wall: 42mm x 4mm Factory Length: 17-7/16 Inch Min. Length: 17-5/8 Inch Max. Length: 18-7/8 Inch Bolt - Both: 14mm Bushing - Both: 611012 JK: Alpine Short Arm Pair - Rear Lower (# 1415540): Tube Diameter & Wall: 42mm x 4mm Factory Length: 19-3/4 Inch Min. Length: 19-3/4 Inch Max. Length: 21-1/16 Inch Bolt - Both: 14mm Bushing - Both: 611011