The device is suitable for use after the 12th week of pregnancy. Features: Color: Blue, pink, purple, green The probe and the main engine are integrated design High precision FHR LCD digital display With headphone design, mothers can listen to fetal heart sound at the same time High sensitivity ultrasonic transducer Low ultrasonic output intensity Low power consumption Volume adjustment Monitoring your baby's heartbeat: With our high-quality fetal Doppler, you can accurately monitor your baby's heartbeat. It will work from 12 weeks of pregnancy and its LCD screen shows your baby's heart rate. You can use ultrasound gel or baby oil to find your baby's heartbeat!