Stanley 77-355 IntelliSensor Pro Metal Stud Sensor Special metal mode detects steel and copper pipes (both ferrous and nonferrous) Reads multiple depths of both wood and metal (1/2", 1", 1-1/2") for outstanding versatility Unique speaker feature provides audible sound when locating studs Multimode LED panel ensures accurate depth indication. Continuous live wire detection for safety Limited Lifetime Warranty