The M10 Stud Sensor has 3 sensors with Multi-Sense Technology. In comparison, similarly-priced stud finders have 1 sensor. With more sensors, the M10 more accurately identifies the center of studs. Using the M10 Stud Sensor is easy. Just press and hold the button to begin scanning the wall and find studs. When scanning the wall, the signal strength will increase as you approach the stud center, and red LEDs will illuminate in sequence until the M10 Stud Sensor pinpoints the center of the stud. When you have found the stud center, the green LED will illuminate.