The device is high performance fetal heart rate detector which satisfies the requirement of hospitaLdinic,community and home FHA examination. The device consists of ultrasonic signal emitter and receiver, computer process unit, LCD display, speaker, keystroke and power supply. Function CL-200A CL-200B CL-200D CL-200G CL-200C Display No B/W B/W Colour Colour Back light No Yes Yes Yes Yes Build-in speaker Yes Yes Yes Yes Yes Battery indicator Yes Yes Yes Yes Yes Curve display No No No Yes Yes Auto power off Yes Yes Yes Yes Yes Alkalinity battery Yes Yes No Yes No Ni-MH battery No No Yes No Yes Adapter No No Optional No Optional USB charging line No No Optional No Optional Voice Optional Optional Optional Optional Optional 2.0MHz probe Yes Yes Yes Yes Yes 2.5MHz probe Optional Optional Optional Optional Optional 3.0MHzprobe Optional Optional Optional Optional Optional