Check for possible hazards before you drill, saw, paint or stain with this handy multi-function detector from Sonin. Detects moisture 8 - 22 percent, finds wood and metal studs, has non-contact voltage detector 1 - 24- VAC, locates metal behind walls up to 2 inches deep. Fast accurate and easy to use LED display with audible indicator. Low battery warning. Uses one 9V battery, not included. One year limited warranty. Avoids carrying around multiple devices for both the contractor and home-owner.