Compact and portable design for convenient use and transportation. The built-in speaker provides a loud, clear voice. Large TFT displays the heart rate of the fetus. Waterproof interchangeable sample. The fully charged battery allows more than 10 hours of continuous operation. Automatic shutdown without operation after 1 minute. The pulse of the 12th-week fetus can be detected with high sensitivity. Three heart rate calculation modes: instant, average 10 seconds and manual.