Tell-Tales are precision gauges uses to monitor movement of a crack, horizontal or vertically on a flat surface. The monitor that consist of two plates which overlap for a part of their length. The bottom plate is calibrated in millimeters and the top plate is transparent and marked with a hairline cursor in the form of a cross. The two pegs are removed. As the crack opens, or closes, the cursor moves relative to the calibration scale. The opening or closing of the crack is then recorded on the crack record sheet supplied.