This revolutionary new tool for wheel and tire installers allows you to get a perfect fit the first time and every time. It eliminates costly returns and delays due to an improperly specified wheel. This tool bolts onto the vehicle's hub to precisely simulate bolt pattern, wheel diameter, wheel width, backspacing, and tire profile. It also allows the installer to check a number of different sized wheels and tires without the expense or hassle of having multiple sizes of wheels and tires on hand.