Stud Finder 4 in 1 Electronic Stud Sensor Beam Joist Finder Wall Detector Edge

Stud Scan: Detects wooden studs at 0.5in (12mm), 1in (25mm), and 1.5in (38mm). 4-in-1 Digital Wall Scanner. Backlit digital screen with depth indicators (½", ¾", 1"). One-touch “MODE” button for easy switching.

eBay