Stop wheel hop and vibrations on hub piloted wheels! Hub pilot hole diameter tolerances can allow wheels to be installed and tightened in an "off center" or clocked position. The 32111 threadless wheel centering tool set (3) fits 22mm studs on Heavy Duty and Over-the-Road Tractors and trailers. These tools slide directly over the wheel studs in the 12, 4, and 8 o'clock positions. The wheel is then installed over teh tools, the stud nuts added to the exposed studs and tightened. The wheel is now centeredprecisely. The centering tools are removed and the final stud nuts are added - torquing all nuts to mfg. specifications. California Residents WARNING