This is a 5 mhz LifeDoppler. It's an audio sonogram device (like used in the Dr. office to check/listen to baby's heartbeat). It normally can only be purchased by colleges or medical facilities. I no longer work or go to school so I have no use for it. I'm selling it super cheap! This is a link to the exact one I have with a better description https://www.medisave.net/lifedop-150-doppler-with-2mhz-probe-7688.html