The device calculates FHR using the DSP techniques that are used in fetal heart monitors to ensure accuracy and reliability. It comes with a high sensitive transducer and uses low ultrasound power for fetal safety. It is friendly and easy to use. Device has a built-in speaker and uses 3 AA batteries with a battery status indicator. To save power, the device will automatically shut off when no function is done for 1 minute in the normal working state. It is 32 in depth, 145 in width, and 97 in height.