These CAD-designed TeraFlex JL 4dr: Alpine Long Arm Brackets are engineered for maximum strength. By streamlining the frame-end mounting points, we were able to incorporate both upper and lower mounts in each bracket thus simplifying installation while maintaining a factory appearance. On higher lifts, Alpine (IR) Long Control Arms (not included) and Alpine Long Arm Brackets reposition the frame-end control arm mounting points to restore near factory orientation to reduce bushing stress during droop and shock load transferred through the control arms. Can be added to an existing suspension lift. Must be used with adjustable Alpine IR Long Control Arms (# 1310505) or adjustable Alpine Long Control Arms (# 1316005) to optimize caster angle and tune anti-squat geometry for proper suspension alignment on JL Wrangler/Unlimited models with 3-6in lifts.