Tell-Tales are precision gauges that consist of two plates which overlap for a part of their length.

The basic Tell-Tale crack monitoring gauge that monitors horizontal and vertical movement across a crack on a flat surface to an accuracy of +/- 1.0mm and by interpolation to +/-0.5mm.

The bottom plate is calibrated in millimetres and the top plate is transparent and marked with a hairline cursor in the form of a cross.

Fix using screws (included).

Supplied with full instructions and Crack Record Sheet.