Product name: Fetal Doppler Detector/baby heart rate monitorItem Type: Feminine HygieneDisplay: LCDScreen size: 44.5mm*23mmFHR Measuring Range: 30~240BPM (BPM: beat per minute)Battery: 2 pcs 1.5V DC battery (not included)Mode: 3 typesWorking frequency: 3.0MHZNet weight: 250gUseful life: 5 years