Since I had first to fight a lot with complications, I bought this device, just to calm me down. It is with the best on the market. Through the headphones you can hear only the even heartbeat, but not too disruptive. When my first child was more the case that it did not want to hear his heartbeat and has floundered very doll. I would recommend it, have used it from the 13th SSW and always found something. Moreover, one need not an expensive ultrasound gel. Etc. Massage Oil does it well.