With a Franklin Sensors stud finder, you have the fastest, easiest, most accurate stud finder on the market. To operate the ProSensor T13, simply press and hold the button then place it on the wall and go. There is no calibration procedure. You can instantly find studs. Once you have it on the wall, the LEDs show you right where the stud is. When you move the unit back and forth, the ProSensor T13 continues to track the location of the stud which makes it easy to instantly see the edges and the center of the stud. Franklin Sensors stud finders are the most accurate stud finders because they have more sensors. Other stud finders typically have only 1 or 2 sensors. The ProSensors T13 has 13. With Franklin Sensors' patented technology, you can find stud positions with unbeatable accuracy. The extra wide display on the T13 allows you to see the full width of objects such as double studs and multiple studs. The ProSensor T13 also features a built in bubble level and a convenient pencil caddy making it the perfect tool for many projects ranging from hanging and leveling pictures, to installing cabinets and flat screen TVs. Once you try the ProSensor T13, Franklin Sensors stud finders will quickly become your favorite. Unlike other conventional Stud finders, Franklin Sensors stud finders detect the studs instantly with crushing accuracy. Franklin Sensors stud finders are proudly made in the USA.