The Extech MO57 Pinless Spherical Sensor Moisture Meter takes pinless (non-invasive) moisture measurements on wood and building materials without damaging the surface. The depth of measurement is approximately <4 inches (100mm). The ball moisture sensor provides smooth gliding on hard or delicate surfaces. The MO57 is easy to operate with display icons that indicate the levels of moisture content as well as an audible alert feature. It is ideal for building restoration projects and applications where moisture detection on floors, tiles and under carpets is critical. The MO57 Pinless Spherical Sensor Moisture Meter is a must-have tool for analyzing the after-effects of water leakage behind walls and in ceilings and also measuring moisture content on a non-flat surface.