1. 7 inch TFT display 2. 2 doorbell units at most 3. 1 Channel display 4. Support monitoring,unlocking,talking 5. Photo capture & video by mobile phone 6. Support IOS/Android system mobile phone and tablet 7. Support wired/WIFI network 8. Support P2P and 4 mobile phones simultaneous streaming 9. With touch-key operation 10. Simple 4- wire connection