Functionality Enhanced: This standard building wall crack monitor is designed to track wall cracks and their progression over time. It serves as a precise tool for monitoring structural integrity, featuring overlapping plates for detailed measurements. Innovative Design: Constructed from two overlapping plates, the bottom plate is meticulously calibrated in millimeters, while the top plate is transparent and marked with precise crosshairs for accurate monitoring. Precise Measurement Scale: Equipped with XY axes, this device offers graduations of ±1 mm (±0.04 in) and a resolution of ±0.5 mm (±0.02 in). It boasts a horizontal range of ±20 mm (±0.79 in) and a vertical range of ±10 mm (±0.38 in), facilitating comprehensive monitoring. User-Friendly Installation: The crack monitor features redesigned mounting posts that securely fasten the two panels together. This design eliminates the need for glue and simplifies the installation process, enhancing both usability and stability. High-Quality Materials: Crafted from acrylic, the crack monitor ensures and stability. The materials not only contribute to the device's robustness but also enhance the clarity of data, making monitoring results easily interpretable. 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: 2 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.