Ryobi E49MM01 Digital LED Pinless Moisture Meter for Softwood, Drywall, and Masonry (9 Volt Battery Included) AUDIBLE ALERTS: If youre looking for the source of a leak behind your work surfaces, listen for the high pitch tones to give you an accurate read on where moisture is most concentrated PROTECT YOUR WORK SURFACES: There are no pins on this tool, so your walls and projects can be saved from scuffing and scratching while you figure out their moisture levels EASY TO READ: The LCD screen shows, in large numbers, the percentage of moisture. This reads up to 30% for wood and relative percentages for walls and masonry DEEP READS: Even without pins, this tool can read the moisture levels up to a half inch deep into your surface of choice OPERATION TEMPERATURES: 32  104 degrees Fahrenheit