Park Tool WAG-4 Professional Wheel Alignment Gauge – For 16-29″ Wheels. For a wheel to perform properly it is important for the rim to be centered between the locknuts of the hub or dished. To check this and to make precision adjustments a wheel alignment gauge (also called a dishing tool) is a must. The Park Tool WAG is an accurate and truly versatile wheel alignment gauge that belongs alongside every truing stand.