... sleep4. 83 effective communication channels, conversation can be stable in any environment5. Improved frequency-hopping technology,super error-correcting ... standards CE, CCC, FCC, R&NTTE7. Ultrashort built-in antenna design, fashionable and attractive shape8. Super-infrared ninght ... approvedAccessory screw, rechargeable battery, ,manual, power adapter Most popular video door phone intercom in China