Ultimate ball joint. Adjustable screw-in mounting. For use in upper location on NASCAR applications. For a variety of racing applications, QA1's Screw-In Style Ultimate Ball Joint is a great choice. This patented, self-lubricating design is 100% owner rebuildable and is exclusive to QA1. Multiple stud lengths are also available, allowing for easy geometry changes. Infinite preload adjustment allows breakaway torque to be set as low as 0 ft. lbs. for a completely smooth, bind-free operation. Precision tolerance ball-to-race conformity results in even load distribution for unsurpassed wear resistance. Precision ground 52100 bearing steel race ensures long life and ultra-smooth operation. No need to remove the ball joint from the car for adjustment. Enhanced by self-lubricating components to ensure smooth operation. Fine tune your roll center. QA1 ball joints are owner rebuildable, and all parts are replaceable at economical prices.