These tubular control arms are built out of 4130 tubing, and TIG welded and offers a 4-lbs. weight savings per side verses stock. The cross shaft is built out of aluminum alloy and has special steel dowels for the bolt and alignment shim pack. The arm also uses a bushing that allows the arm to fall under its own weight, making weight transfer very fast. There is additional positive caster built into the control arm for straight-line stability. The arms are powder coated black and shipped fully assembled