Usage 1. to Zero to “test”. 2. Press the Knife Plane to the Rest, the Rotation Pointer Will Indicate the Zero Position, Turn the Table Ring to Make the Large Pointer to the Zero Position 3. when Used on “use” to Zero. 4., Put the Tool Set on the Workpiece, Switch the Magnetic Base Switch to "on", Slowly Feed the Tool to the Tool Face, Make the Big and Small Pointer at the Same Time to Zero, then the Distance Between the Tool and Workpiece is 50mm/2in.