Grand Index 4-in-1 Non-invasive Inductive Moisture Meter Sk318 for Drywall, Masonry, Softwood and Hardwood w/ Auto Calibration & Alarm Detect Moisture of 4 different materials (drywall, masonry, softwood, hardwod) Audio Alarm if reading is out of range Moisture display on LCD and LED bars Measure moisture without damaging the surface Ideal use for wood / timber industry, building material storage drywall, fabric and paper