The crack measuring instrument is made of high-quality acrylic material, which is durable, strong, smooth, wear-resistant and not easy to break.<br> Designed with highly transparent acrylic panels and easy-to-read measurement grids, our crack monitors are clear and precise. This is very practical .<br> You can use our corner crack monitor to monitor the horizontal or vertical movement of cracks on a flat surface. It is a .<br> Tell the story of 2D manual crack monitoring work. Crack monitors are used to monitor wall cracks and their .<br> The base plates of our crack measurement tools are calibrated in millimeters. It also has a transparent top plate marked with a -shaped thin line cursor.<br> Material: Acrylic<br> colour: transparent<br> Package Contents:<br> 1 x crack measuring instrument<br> Only the above package content, other products are not included.<br> Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.