These direct - fit rear upper control arms add strength, on - car adjustability and articulation flexibility ot your stock - height or 'lifted' suspension Wrangler. They feature SPC's xAxis sealed flex joints mounted in forged rings on the axle ends to provide bind - free 'twist' between the frame and axle during off - road articulation. The dual - threaded adjuster and jam nuts make rear pinion angle adjustments quick and easy without the need to disconnect the arms. Main tube is 316 wall DOM steel for 'overkill' strength to handle large tires, low gearing, and big horsepower. California Residents WARNING