[ Acrylic Construction]Crafted from superior acrylic, this crack monitoring device offers exceptional durability and resistance to weather elements. It's designed for repeated use, boasting features like waterproofing, sunproofing, and resistance to wear and scratches. Installation is straightforward, and the device provides clear, intuitive readings. [Advanced Technology]Equipped with cutting-, this crack monitor gauge is perfect for accurately tracking both horizontal and vertical movements of cracks on flat surfaces. It ensures dependable monitoring of crack width or length changes over time, making it an essential tool for structural monitoring. [Comprehensive Monitoring Capabilities]Designed to meticulously monitor wall cracks and their progression, this device includes a scale plate with horizontal and vertical scales and an indicator plate with crossed lines. It offers a measuring range of ±1 mm (±0.04inch) on the X-Y , with a resolution of ±1 mm (±0.04inch), and extends up to ±25 mm (±0.98inch) horizontally and ±10 mm (±0.38inch) vertically. [Versatile Application]Ideal for observing crack dynamics and misalignments on building surfaces, this instrument also tracks relative displacement between two points in both horizontal and vertical directions. Its versatility makes it suitable for a wide range of structural monitoring applications in construction and engineering fields. Screws: random color, don't accept the specified color Colour:transparent Material:Acrylic The actual product may have slight color difference or difference, which not affect the use Package Contents: 4 x Crack Monitoring Record Only the above package content, other products are not included. 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.