do you mean like one of those heart dopplers wher eyou can hear the heartbeat?
i have one, i didn't get to use it for this pregnancy, but my 1st, i was going to use it, had it set up, but never had the time lol.. i think it's a great thing..
i think mine is around in the closet somewhere
i know they have new ones though where you can play music too or record the heartbeat (i think that's what mine was able to do)..