Park tool wheel alignment gauge wag4for 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 an accurate and truly versatile wheel alignment gauge that belongs along side every truing stand featuresthe wag 4 allows easy checking of the dish on road mountain or bmx wheels from 16 to 29 etrto or isorim sizing of 3