Description:Baby Heartbeat Monitor: Suitable for monitoring the heartbeat, kicks and moves of unborn babies.Large LCD Display Screen: With big LCD display for convenient operation.Practical Tools for Pregnant Moms: Pregnant moms can operate the baby Doppler by themselves to hear fetal heart sound and calculate FHR.Sensitive Probe for Clear Sound: 3MHZ Doppler probe, ultrasonic baby heartbeat detector, low ultrasound power, safe and accuracy.Realizing the purpose of Pre monitoring and fetus caring. (Powered by 2x AA batteries, not included)Specification:Material: ABS plasticProduct size: 135x98x30mm/5.31x3.86x1.18inchRated voltage: DC 3VBattery Type: 2x AA batteries ( not included )Fetal heart beat range: 50BPM-230BPMUltrasonic frequency: 3.0MHzFetal heart beat measurement accuracy: 2BPMWaterproof grade: IP5 dustproof and waterproofPackage Includes:1 Piece Fetal Heartbeat Monitor1 Piece ManualNote:Lie down on your back, apply couplant to the probe after turning it on, press the belly with a little pressure, and move the probe slowly. Start looking at the bottom, and when you hear a regular clucking sound, it's the fetal heart sound. Press the probe tightly, and the machine will measure the baby's one-minute fetal heartbeat in about a few seconds. The normal heartbeat range is 110-160. After hearing the correct fetal heartbeat, look at the data. The data that appears when the fetal heartbeat is not heard is invalid.The fetal heartbeat is not fixed, it fluctuates up and down. The value that appears on the screen a few seconds after hearing the baby's fetal heart sound is the baby's average heartbeat.