1. Material: Made of acrylic, our crack gauge is durable, sturdy, smooth, wearresistant, and resistant to breakage. The Crack Monitor features a clarity acrylic plate with an easytoread measuring grid for clear and precise readings. 2. Easy to Use: First, secure it with two adapters, then align the crack center with the crosshairs before sticking or placing it over the crack. Finally, fix it to the wall using screws and expansion anchors. 3. Creative Updated Fixing Options: The upgraded design includes two fixing adapters, allowing onehanded installation with zero hassle. Our Corner Crack Monitor can track horizontal or vertical crack movement in a single plane, making it a precision instrument. 4. Accuracy: Vertical measurement: ±1 mm (±0.4 inch) markings on XY axes; ±0.5 mm (±0.2 inch) discrimination. Horizontal measurement: ±20 mm (±0.79 inch) range horizontally and ±10 mm (±0.38 inch) vertically.