You can use the angle crack monitor to monitor the horizontal or vertical movement of cracks on a plane. A precision instrument. The crack measuring instrument is made of high-quality acrylic material, which is strong, smooth, wear-resistant, and not easy to break. Relates to manual 2D crack monitoring work. Crack monitors can monitor wall cracks and their progress. Designed with highly transparent acrylic panels and easy-to-read measuring grids, our crack monitors are clear and accurate. Very convenient for you. The base plates of our crack measuring tools are calibrated in millimeters. It also has a transparent top plate marked with a thin crosshair cursor.