Function:
1) Audio/video communication
2) 4'' flat B/W CRT(3.5'' /4.0''color digital TFT LCD)
3) monitor door entrance
4) Remote lock release
5) Inter-call with extended phone set
6) Optional for extended camera or extended monitors.
7) Optional extended panel for apartments more than 24 in a building.

Data of technology
1)working voltage: AC11V~220V
2)working current: <400mA
3)wiring: 4 wires
4)Ambient Humidity: 45%~95%
5)Resolution: 420(W)*380(H)
6)Video Output: 15625Hz 1Vp-p 75Ω, PAL or NTSC
7)installation method: Surface mounting type.