Fetal Doppler_DS120A 1.Automatic power off 2.LCD display with backlight,easy to operate. 3.reliability of FHR detection Fetal Doppler ... hour >4 hours Others *Measuring Mode Mean, Average, Continuous, Backlight*Display 3 digital FHR,Battery low,Voice,Ultrasound frequency,Mode ... 0.5W*Auto Shot Off 20s FEATURE 1.LCD display with backlight, can be used in any illumination conditions.2.DSP technology ...