This is a remarkable stud sensor. Not only is it easy to use but its readings are practically impossible to misinterpret. At 7wide it covers a broad test area with sensors that independently scan up to 1 1/2below the surface. As soon as any of the 13 sensors detects material of greater density than the surroundings they display its position using 21 closely-spaced red LED bulbs highlighting precisely where the obstruction lies. Wide enough to span most structural timbers the LED array can indicate the full width of the stud not just the edges so finding center is simple C no need to sweep back and forth to outline the location. As well unlike typical detectors the sensors require no calibration before each use to prevent false readings; just place the unit against the wall and press the button for an instant reading. A reliable means to locate studs as well as floor joists or other hidden substructure behind drywall wood and plywood it even differentiates closely positioned studs such as those around door and window frames. It also detects live electrical wires behind walls. A low-friction backing glides smoothly over surfaces and a built-in level helps with marking. Intuitive to use it operates on two AA batteries not included. An excellent tool. Made in USA.

Franklin Sensors ProSensor M210 Center and Edge Professional Stud Finder
$48.99