Safe: Ultrasound dosage is under 50% of the standard. - Portable: light measure, handset, portable. - LCD display: LCD display FHR - Loudspeaker: Built-in loudspeaker & clearly - Power off: Auto- power off function. - Working time: Adopt with recharger battery, constantly working 10 hours over when full of recharger. - Durable: Huge capacity battery, work more than 12 hours after full charge. - Convenience: Single key control. Automatic battery recharge and protection. - Sensitivity: Monitor 9 weeks above unborn babyÆs blood wall pulsate. - Three model account: Real-time, ten seconds average & handly account the FHR.