With a highly sensitive ultrasonic probe, this fetal heartbeat is easy to find the baby's position and detect the heartbeat for pregnancy care. The built-in speaker with volume control is of clear sound quality and the LCD screen can real-time and accurately display fetal heartbeat. It is a good way to develop the relationship between baby and mother. 

• Model no: YK-90B. 
• Color: pink, blue, purple, green. 
• Origin: China. 
• Material: ABS. 
• Weight: 0.3kg. 
• High precision FHR LCD digital display. 
• Main body and the probe are designed separately. 
• Built-in speaker to play the fetal heart sound. 
• High sensitivity ultrasonic probe. 

Overview:
Yonker Fetal Doppler applies the ultrasonic doppler principle to obtain the movement information of the fetal heart from the abdomen of pregnant women, enlarge the signals, and output them from earphones so as to calculate the value of fetal heart rate.

• Product composition: One-piece design, consisting of a host and a probe.
• Ultrasonic operating frequency nominal operating frequency: 2.0MHz or 2.5MHz (see probe label for details), deviation less than ± 5%.
• Fetal heart rate measurement range: 50~240bpm.
• Comprehensive sensitivity at 200mm from the probe surface: >90dB.
• Space peak time peak negative sound pressure P (MPa): P_<1MPa.
• Peak time peak sound pressure: < 0.2MPa.
• Ultrasonic output power: < 40mW.
• The effective area of ultrasonic transducer sensitive components: 157mm2±10%.
• Working mode: continuous wave.

How to use:

• Before using it for the first time, make sure 2 batteries are in.
• Press the power button to power on, then adjust the volume.
• Lie flat with a cushion pillow, keep your legs straight and relax.
• Attach the fetal probe to the abdomen to locate the position of the fetus and find out the best direction to the fetal heart.
• After hearing regular fetal heart sounds, the FHR value will display on the screen in real-time.