and wall-mounted office monitors. Bosch’s GMS120 is more than just a stud finder (though it located the centers of those we tested it on within an eighth of an inch). It also detects live AC ...

Ryobi tools are often well-reviewed by their owners, but a good stud finder is hard to find. Does Ryobi's measure up, or are ...

The Bosch Professional Stud Finder GMS 120 ($74.11 at Home Depot) uses this technology. Walabot makes a sensor that pairs with a cellphone to provide images showing hidden objects within a wall.