Radial Run-Out Gauge is an out of round condition in which the radius of the wheel or tire is not consistend from the wheel center to any point on the rim or the tread. Tire and wheel radial run-out are often factors in troubleshooting ride and handlingand in maintaining correct wheel balancing to reduce vibration. 64250 Includes: Heavy duty tripod, wide machined roller, Accurate pin-pointer, Ball Joint/Tie rod extenders.