From the Manufacturer
It is essential to know the moisture content of your wood BEFORE using it in any project. The use of wood with a high moisture contect could be disastrous to your finished work. Warping and checking could ruin days and weeks of hard work This meter measures moisture contect of any lumber including fabricated woods, hardwoods, and soft woods. Measures 6-24% moisture content
Simply insert the meter pins into the wood and press on/off switch. Bright LED readout gives you an instant, accurate reading from 6% to 24%.Comes with protective cap, instructions and 9-volt battery.