features：
display: lcd screen
performance: fhr value
range&accuracy: fhr measurement range: 50~210 bpm
accuracy: ±2bpm
measuring mode: real-time
ultrasound frequency: 2.5mhz
dimension: main body: 122.5× 59×37.4(mm)
pedestal: 92×98×46(mm)
net weight: main body: 74g
pedestal: 65g
backlight and speaker: backlight, adjustable volume
battery type: iec6f22 9v alkaline