1. Measuring range: 60-210bpm 2. Material: plastic 3. Voltage: DC 3V 4. Output ultrasonic power: less than 20mW 5. Power supply: 2 No. 5 alkaline dry batteries (not included) 6. Size: Approximately 12x9.3x3.1cm 7. Weight: about 250 grams Peculiarity: 1. LCD white screen, fetal heart digital display 2. Using ultrasonic Doppler detection technology, low output power, can be assured of daily fetal heart rate monitoring 3. Independent probe design, simple operation, high sensitivity wide beam, 2.5MHz probe to ensure reliable measurement during pregnancy 4. Using digital filtering and noise reduction technology, it can reduce other noise except the fetal heart, optimize sound processing, reduce background noise, and make the fetal heart heart sound clearer 5. The autocorrelation algorithm can effectively eliminate the interference of the external environment, suppress the noise in the echo signal, and measure dynamically and accurately 6. Two listening methods, headphones/amplification 7. High-fidelity speaker, low-power design, adjustable volume 8. If it is not operated for 2 minutes, it will automatically shut down, saving energy and reducing consumption