-Earphone and speaker are feasible -High sensitivity doppler probe -Low ultrasound dosage -Display with color 45*25mm LCD -Ultrasound frequency: 2MHz -Ultrasound Intensity: <10mW/cm2 -Power :AC 220/110V, 50/60Hz; DC 2pcs of Ni-MH rechargeable battery -FHR Measuring range: 50-240bpm -FHR resolution: 1bpm -FHR accuracy: ±1bpm -weight: 500g