From the Manufacturer Tune your planer within .001" tolerance in 15
minutes or less with the Magna-Set Rotacator. This dial gauge has a
magnetic base to hold it firmly to the bed of the planer while taking
measurements. The dial guage rotates to take measurements both top and
bottom for added versatility. An invaluable aide in adjusting feed
rolls, chip breakers, bed rolls, and knives. The .250" range of
travel allows for all common applications. Includes one magnetic dial
gauge.