AngelSounds---JPD-100S Functions and Features: Range: A family use Ultrasound product. The pregnant women can hear the fetus? heart beat even stay at home. It can be connected with the long-distance monitoring system in hospital, make the fetus under the protection of hospital at any time. Safe: With small Ultrasound dosage, only 1/10 of the international safe standard. It won?t do any harm to fetus even long time use. Convenient: With small main body; easy to use; do not need professional training. Sensitive: It can monitor the FHR of fetus 12 weeks up. Economical: Cost about USD30 only, it is easy to be accepted by the pregnant woman, enable the popularization of the long-term monitoring outside of hospital. Main Technical Specification: Ultrasound frequency: 0.8MHz-2.2MHz ±3% Ultrasound intensity: ＜5mW/cm2 Power: DC 9V dry battery Size: 120mm?105mm?65mm Net Weight: 0.11KG