Best High-Tech Fetal Heart Monitor - checkpregnancy.com - Little Martin’s Baby Sound Amplifier and Recorder
"Unlike the “computer mouse” style of most fetal doppler monitors, the Little Martin’s Baby Sound Amplifier and Recorder are designed more like a cell phone. The probe takes up nearly half of the unit, and it offers an LCD backlit display and sleek external casing."
Source: https://www.checkpregnancy.com/best-fetal-doppler-moniter-pregnancy-reviews/