Clear Fetal Heart Sound. Normal Fetal Heart Rate is usually between 110 and 200 beats per minute. The fetal heart rate may change as your baby responds to conditions in mother's womb. Since, its a doppler therefore it is user dependent and requires practice to operate. Results can vary depending upon the operator's skill and practice. LCD Display. High Sensitivity. Perfect to listen and record your unborn baby's heartbeat when he/she is 12 weeks above. Lightweight and easy to carry. Material: ABS Plastic. The product does not contain any couplant. We recommend using a couplant instead of the common aloe vera gel, also known as ultrasonic couplant. Use of couplant gel is a must for satisfactory results. For detailed safety instructions and other requirements, read the Operational Manual provided with the product. Please make sure that you carefully read the Operational Manual before using the product. After turning on the device, apply gel on the probe, lie down, press the probe on the belly with a little force, and slowly move the probe to search for fetal heart rate. When you hear a regular roaring sound, it is the fetal heartbeat. The product body has a built-in intelligent noise reduction and sound insulation unit, which can effectively reduce noise and make the output clearer. The product has high sensitivity waterproof probe. The product has no radiations and safer to the fetus. Now you can share your joy - a healthy and strong heartbeat with your lover, families and friends, whether you are at home or out. BPMPower: 2x AA battery (For transportation reason , batteries are not allowed to be shipped, you need to arrange it yourself).