The BPL Fetal Doppler FD-02 is a portable, handheld device that uses ultrasound to monitor a fetus's heartbeat, featuring a clear LCD screen, a high-sensitivity 2.5 MHz probe, and both a built-in speaker and headphone jack. It is designed for home or clinical use, can detect heart rate from around the 16th week of gestation, and includes features like smart alerts, auto-shutdown, and a rechargeable battery.