Ultrasonic leak detector can locate leaks in compressed-air systems. Testing of unions, pipes, valves and fittings can be completed from distances up to 20' away. High-pressure air expanding to atmosphere creates a high-frequency turbulence that the unit converts into an audible tone that can be heard through supplied headphones. As the instrument moves closer to a leak, LEDs on the display light up to confirm the source. A parabola attachment pinpoints leaks and a tubular extension masks out intense background noises.