Product description: 1. Light weight and portable, easy to use. 2. Long life design, dust proof. 3. Battery save design, standby for 3 months or continual used for 5 hours. 4. Large backlight LCD display FHR. 5. Built-in Hi-Fi speaker, clear fetal heart beat sound. 6. Accurate FHR detection, has real time FHR mode and average FHR mode. 7. High sensitivity interchangeable probe. 8. Audio out put port. 9. Optional rechargeable battery and charger.