5-in-1 Unlock: Our video doorbell has 5 unlocking methods. You can unlock by password, fingerprint, IC card, APP, and monitor. It is very convenient and flexible. 5 passports are included. Allows you to open the door whenever you want. About Wiring: The doorbell monitor needs to be wired with 4 wires. We provide a 3m 4-core cable for each doorbell for basic installation, a 1.2m external power supply for each monitor. You can extend the distance with a 4-core wire. The main monitor can be connected to your home Wi-Fi network. Allows you to view visitor information on your mobile phone at any time. Two-way Audio: When someone rings the doorbell, all monitors and phones will ring. (You can see, hear and speak to everyone in front of your door and never miss any visitors. (You can open and unlock the door with any monitor. You can connect all 12V electronic locks.) All monitors support call transfer or internal speech (audio only) between indoor monitors. 7 inch Touch Screen & 1080P