Zircon StudSensor Pro SL Edge Finding Stud Finder: * Locates edges of wood or metal studs up to 1.5"" deep * Easy-to-read LED display and audio tone indicates stud edges * TruCal instant calibration ensures accuracy * Works on extra thick wall coverings, ceilings and floors * Finds wood and metal studs, joist and beams behind drywall, plaster and wood * Sound indicator beeps when stud is found * Electronic precision * Fully automatic * Non magnetic * Spotlight indicator * Uses 9V battery (not included)