Crack Width Gauge for Concrete CW-02 5PCS

31 precision crack widths mm: 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95. 1.0 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 Metric Ruler: 0.01cm - 16.5cm, Marking Resolution 1mm Break resistant molded polycarbonate suitable for indoor or outdoor use Thermal expansion coefficient α: 70 µm/m/°C from -30°C to +30°C No parallax: bottom printing virtually eliminates parallax and measurement distortion