Other details keeping track of your baby s heart rate and helping determine the strength & duration of your contractions. Bpl fd, 01 is an ultrasound foetal doppler that is safe designed for application on every pregnant women. It presents an auditory representation of the monitoring the heartbeat of the fetus via Doppler technology effect. With a sizable LCD display display capable of showing foetal heart rate from 16th week of gestation. Bpl fd, 01 comes with 3. 0 mhz high sensitive ultrasound probe and built in loud speaker. Low battery indication and auto shut down feature saves battery life. Accurate fhr foetal heart rate detection & completely safe for the foetus and mother lacking any accompaniments effects. Real time, Average & transient fhr calculation modes audio headphone jack and built, In loud speaker for quality foetal heart sounds.