Features: Brand new and high quality High-Quality Material: Crack Gauge Monitor is made of high-quality acrylic material, so it is durable, sturdy, smooth, wear-resistant, and not easy to break. Clear and Precise: Crack Monitor is designed with a highly clear acrylic sheet and an easy-to-read measurement grid, so it is clear and precise. It is very practical. Crack Monitoring: Corner Crack Monitor is a simple and cool analog-crack monitoring device and a precisions instrument used to monitor the horizontal or vertical movement of cracks on a plane. Great Purpose: To tell the story of manual crack monitoring work. Crack Monitoring Gauge is used to monitor cracks in wall and how they evolve measured. Design: Crack Measurement Tool consists of two boards that overlap for part of their length. The bottom plate is calibrated in millimeters, and the top plate is mark with a thin lines cursor in the shape of a cross. Specifications: Material:Acrylic Size:Approx. 100x30x9mm/3.93x1.18x0.35inch Package Includes: 1 Set Crack Monitor Gauge note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.