STA077355 IntelliSensor ProMetal Stud Sensor with Metal Scan The IntelliSensor ProMetal Stud Sensor with Metal Scan locates the edges of wood or metal studs or joists through drywall and other common wall materials at a maximum depth of 38mm. It has an audible tone to indicate stud and joist edges. The unit requires a 9V battery (not included) with automatic shut-off for longer battery life. Continuous live wire detection