Feature●Tell-Tales are precision gauges that consist of two plates which overlap for a part of their length. The bottom plate is calibrated in millimetres and the top plate is transparent and marked with a hairline cursor in the form of a cross.●Supplied with full instructions and Crack Record Sheet & Fix using Screws and Adhesive●±1 mm (±0.04") tick marks on X-Y axes; ±0.5 mm (±0.02") discrimination●±20 mm (±0.79") horizontal and ±10 mm (±0.38") vertical range●The redesigned fixing column can easily fix the two pieces together without the need for glue. Crack monitoring scale is used to monitor the cracks in the walls and how they evolved along the measured time.High-quality polymer with easy-to -read measurement grid,Description Tell-Tales are precision gauges that consist of two plates which overlap for a part of their length. The bottom plate is calibrated in millimetres and the top plate is transparent and marked with a hairline cursor in the form of a cross.The redesigned fixing column can easily fix the two pieces together without the need for glue. Crack monitoring scale is used to monitor the cracks in the walls and how they evolved along the measured time.High-quality polymer with easy-to -read measurement grid,