The Video Door Phone facilitates two way communication > It can connect to up to 2 Outdoor units and 4 Indoor units > Facilitates simultaneous Monitoring and talking with a visitor > 7 inch ABS-panel indoor monitor with touch buttons and 16 mm thin design > Indoor Monitor has 800*480 resolution. > It can support an external analog CCTV camera > E supports intercom > Remote unlock and monitor the door. > Adjustable talk volume and ringing volume. > Input call be transferred from one indoor monitor to another. > Use with Home automation system and Smart Locks.