The Extech MO280 provides Non-invasive moisture measurements in wood and other building materials with virtually no surface damage. Meter uses electro-magnetic technology to quickly indicate the moisture content of wood and building materials. Select from 10 wood types and measurement ranges. The LCD displays % moisture of wood or material being tested. It has a measurement depth to 0.75 in. (22mm) below the surface. The meter also features an automatic internal test and calibration and low battery indication.