LCD display FHR ;Built-in loudspeaker & clearly ; Auto- power off function. Adopt with recharger battery, constantly working 10 hours over when full of recharger; Huge capacity battery, work more than 12 hours after full charge; Single key control. Automatic battery recharge and protection; Monitor 9 weeks above unborn baby’s blood wall pulsate; Real-time, ten seconds average & handly account the FHR. Specification: Probe: Solid and durable, anti-shock and anti-falling down. Power: DC 7.2V Size: 133mmx85mmx31mm,Weight:Main body 0.12kg Temperature: 5℃-40℃,Humidity: 0-85%