Pro Ultrasonic Leak Detector & Industrial Stethoscope,High Sensitivity Machine Diagnostic Tool for Engine Noise, Bearing, Valve, Pump, Pipe Flow,Mechanic Tool Kit(Includes Long/Short Probe & Carry Bag)

For an inexpensive toll it worked just fine. Not terribly sensitive and as others have commented, it has to be touching a surface to work. You can’t wave it in the air and expected to pick up any sound whatsoever.

This is a decent-quality *contact microphone*, and quite sensitive for detecting vibrations and internal machinery noise. However, it barely picks up ambient sounds, so I was unable to use it to localize the hissing air leak in a pneumatic system. The description says "Air Leak Detector", but I found it unsuitable for that purpose and returned it.

Works great. It's very interesting to listen to the valve train and fuel pulses on my car's engine. With this device, I believe I know the source of this noise is just an artifact of the engine's design, and nothing to be concerned with.

It's a little bit better than a manual stethoscope. At least I don't have to get close to finding a noise with my head. The headphones have a long enough cord that you can keep out of the way of dangerous equipment when trouble shooting. Great amplification vs. no amplification with the manual stethoscope.

Junk., garbage., waste of money

It probably works to find a nock or tap but does not work for AIR!!!

I use this to pinpoint leaking seals in pcp air rifles. Does a nice job.

Didn't know these existed until Amazon brought it up in a search. We use it to find problem components inside PCs and Servers. Works great.

Does what is should. Build quality is fine.

Excellent tools

muy rapido al entregar y muy bueno el equipo, gracias

Works great. Head phone is cheap. Have to try better headphones. If they work this item would be great.

Used to look for pool leak. Amazing results