Features and Benefits: * Quick diagnosis of leaks * Convenient easy to use * Internal noise control * Easily pinpoints the exact problem source * Self-adjusting gain control enhances sensitivity Comes complete with ultrasonic receiver, ultrasonic emitter, air/extension probe, contact probe, headphones and rugged carrying case. Features advanced heterodyne circuitry and “sound signature technology” to convert and amplify inaudible ultrasonic sounds into audible “natural” sounds. Provides quicker diagnosis of leaks and defects before they result in major breakdowns! Detects air brake, compressed air, vacuum, EVAP system and other pressurized leaks quickly and effortlessly. 5-LED signal intensity indicator and audible alarm easily finds exact problem source. Powered by two “D” cell alkaline batteries (included).