This device allows hearing the heartbeat of a fetus from a builtin speaker as early as 10-12 weeks, and warns in case of serious problems of the fetus. For home and hospital use. Supplied with gel bottle, 3 AA batteries and user manual.Portable and lightweight Built-in speaker to hear fetal heartbeats, Numeric and trend curve display for FHR, Automatic power-off function, Backlight LCD display, Date, time, battery status display, Audible & visual FHR alarm, Audio-out interface, Fetal monitor DSP technology, High-sensitivity probe,1 MHz working frequency.