FEATURES: Consists of two plates with overlapping section lengths. The lower plate is calibrated in millimeters, and the upper plate is transparent and marked with a crosshair. PREMIUM MATERIALS: The crack monitor is made of high-quality ABS and acrylic materials with excellent durability and stability. At the same time, the choice of materials ensures that data is easy to read and provides clear measurement results. FUNCTION: This standard wall construction crack monitor is used to monitor cracks in walls and their development during the measurement period, making it a practical and accurate measuring instrument. SCALE: Has a scale division of ±1 mm (±0.04 inches) on the XY axis with a resolution of ±0.5 mm (±0.02 inches). The horizontal range is ±20 mm (±0.79 inches) and the vertical range is ±10 mm (±0.38 inches). EASY TO USE: With the specially designed mounting rod, you can easily attach the two boards to each other without the need for glue or complicated assembly steps. This ensures greater ease of use and stability.