... CE approved Pocket Fetal Doppler Details: Fetal Doppler is a safe and easy to use device that has been ... detection, standard on Hunt Leigh FD1+ and D920. A full bladder can make it easier to find the heartbeat ... batteryContinuous working hour>4 hoursOthersMeasuring ModeMean, Average, Continuous, BacklightDisplay3 digital FHR,Battery low,Voice,Ultrasound frequency,Mode typeButtonON/OFF, Voice Control, ...