LCD display:Large backlight LCD displays the fetal heart rate. 

Loudspeaker:Built-in speaker gives clear and loud voice. 

Interchangeable waterproof probe.

Automatic shutdown function in case of no work for one minute.

High sensibility can detect the pulse of 12 week fetus.   

Three calculation modes to calculate fetal heart rate: instant, 10 second average and manual.

Ultrasonic frequency: 3.0MHz ±3%

Power:AA*2