Includes 4 batteries The 3-D Electronic Sensor has four LED indicators. High sensitivity sensors for fast and accurate positioning in manufacturing applications including milling and turning. Indicators light up at the slightest touch to their sensors. Features Zero finding fast and extremely accurate on all axes X, Y and Z. Operates in horizontal or vertical position. Can be used for X and Z location for CNC turning, X, Y and Z for machining centers and for centering and measuring round holes. Probe diameter .200" Shank diameter .750" Z-axis to reference surface 2"