Basically a precision engineered 'torch' that can be mounted in the tool holder of a milling machine. When the circuit between the main body of the tool and the 'probe ball end' is completed, using the normal metal to metal connectivity of the machine between the quill and a metal workpiece, a bright indicator light, housed in the body of the tool is turned on. The 'probe ball end' is a precise 10mm diameter, concentric with the axis of the tool holder, so the 'touched edge' can be calculated as plus or minus 5mm from that point. The height of the work face can also be measured. Available with a 20mm parallel shank for use with collet holders or chucks, the edge finders provide a quick, accurate and trouble free method of establishing location data.