Part No.: HMP-M103 Feature: 1. Radio: Hand and auto scan inside FM88-108M Hz. 2. Interphone: 10 channels interphone system. The max talking distance is about 200 meters (no hidrance). 3. Low power: 3V power supply. 4. Memorize frequency in the radio mode. 5. Memorize channel in the interphone mode. 6. E-volume and power down automatically. 7. Pen designed: writing smoothly and can be replaced conviently.