This is the RPM Toe-In Gauge. Our Toe-In gauge allows you to do track-side checks of the toe-in without removing the wheels! Our gauge checks toe through the simple method of comparing the distance between the wheels at the rear of the tire to the distance between the wheels at the front of the tire! Our gauge is accurate to within one half of a degree per side and closer! Also can be used to check legal width of off-road buggies and trucks. This gauge includes a second adjustment hole to check narrower vehicles such as sedans as well!