Stanley Tools 77-050 Stud Sensor 50

The S50 stud finder detects wood and metal studs up to three quarters of an inch below surface material and features auto-calibrating AC detection. With a sturdy design, this stud finder indicates when it senses a wood or metal stud below the wall surface. Sequential LEDs mark both the edges and center of studs with accuracy up to 1/8 in. for wood and 1/4 in. for metal.