The "Fetal Doppler Digital (Deluxe) (FDP066)" is a portable, at-home device that uses ultrasound technology to let expecting parents listen to their baby's heartbeat, often starting around 12 weeks into pregnancy. It features a digital display to show the fetal heart rate (FHR), a built-in speaker for listening, and a headphone jack for private listening. The "Deluxe" model likely includes advanced features like interchangeable probes and clear sound quality.