UMI Performance adjustable upper control arms allow you to adjust your vehicles pinion angle for optimum performance, precise handling and improved traction. Adjustable upper control arms are constructed of CNC machined 0.250" steel mounting plates, 4140 chromoly threaded tube adapters and a high strength, 4140 chromoly, heat treated 1.000" solid adjuster. UMI Performance's unique on-car adjuster allows for easy adjustments with out removing or unbolting the control arm from the vehicle. Adjusting your vehicles pinion angle is must when wanting to lower your track 60-foot times, increase traction and reduce unwanted wheel hop. These control arms also feature grease-able Energy Suspension fluted polyurethane bushings and durable gloss powder coat.