The device features a backlit LCD screen that displays the fetal heart rate (FHR) in real-time. Operating Frequency: It typically uses an ultrasound probe with a frequency of 3.0 MHz (as seen in the image) for clear sound detection. Audio Output: It includes a built-in speaker and often a headphone jack for private listening. Portability: Designed to be lightweight and compact, making it easy to use and carry. Power: Usually powered by batteries (such as AA) or can be rechargeable depending on the specific model. Usage Information How it Works: The device applies the ultrasonic Doppler principle to detect the movement of the fetal heart through the mother's abdomen. Preparation: It is designed to be used with ultrasound gel (sometimes included) to ensure a clear signal