Multi-crystal pulse wave Doppler waterproof transducer for FHR detectionPulse Repetition Rate : 2 KHzPulse Duration : 92 usUltrasound Frequency : 1.0 MHz +-10%FHR Measurement Range : 50bpm - 240 bpmFHR Resolution : 1 bpmFHR Accuracy : +- 1 bpm