Turn the button of setting- zero from "use" to "test";

Press down,the small indicator will show "0", keep your hand and then adjust indicator to be zero at long- needle;

Turn the button of setting—zero to "use" before use;

Put on the work piece ,cutter touch probe side ,when the long-needle and short- -needle moving to "0" at the same time,the distance of the cutter with work piece is 100mm.