Baby Sound A is a pocket fetal Doppler device used to detect fetal heart rate (FHR). It is specially designed for pregnant women to conduct daily detection of FHR themselves. Pregnant women can hear fetal heart sound and calculate FHR for the purpose of pre-monitoring and fetus caring. The probe and main units integrated together. Its compact design makes it portable to use. It includes 2 headphone sockets for expectant parents to hear the fetal heart sound together. It is equipped with a High sensitive Doppler probe. Its ultrasound output intensity is much lower than the relative government standard which is safe. It operates using two AAA size batteries that can last for more than 8 hours of continuous use.