Detailed Product Description

Features:

1) One door station can support up to 4 indoor phones.   

2) Handset B/W video door phone with 4"CRT screen and CCD or CMOS camera.             

3) LED in the door station provides a clear picture even in nighttime.

4) 10 seconds ring tones, 30 seconds active surveillance and 120 seconds intercom are available.

5) Double ding-dong ring,remote door unlocking and waterproof are available.

6)Connection:4 or 5 wires

7) Panel: Plastics

8) Installation:

a) For door station:surface or flush mounting

b) For indoor phone:surface mounting

PS.  681B is black and white video

       681C is color video