Just got this in today. And OMG I am in love. I have used this for almost 3 hours now. You can hear the babys heartbeat perfect. It is amazing how this product works. I was hesitant to buy it, the company gave me a small discount if I was to review it, and I decided to take the offer. I thought what the heck it is cheaper than other ones, and I looked it up on facebook and it looked good. And now that I got it, I love it. It works perfect and so well. I did use my own headphones just because I have expensive ones and I like them. This is such a great product Im planning on buying one for my cousins wife. I also like that it has an app and you can record the heartbeat and have it on the computer. I love it. This is an awesome product. I am so glad this product works. Works perfect. U have to place it right and find .