The Stanley S160 Stud Sensor detects wood studs up to 25mm in depth and metal studs up to 38mm in depth. It also detects the presence of AC live wire within a 15-45cm radius and up to 50mm depth. Single button for simple operation. An audible alert provides clear notification of stud detection whilst directional LED lights provide visual guidance to stud location. Auto-calibration helps to avoid missed studs due to incorrect initial calibration. With a slim profile design for easy storage and portability. A centre marking channel allows for accurate stud markings. Ideal for locating studs to enable tasks such as TV mounting, hanging pictures and shelves. Specification: Max. Detection Depth: Wood Stud 25mm, Metal Stud 38mm Input Power: 2 x AAA batteries (supplied)