There are a lot of reasons for it. For one thing, it means you can give guests a real-time heads up about when to expect you to answer the door instead of just making them wait outside.

Why Would I Need a Video Intercom System?
There are a lot of reasons for it. For one thing, it means you can give guests a real-time heads up about when to expect you to answer the door instead of just making them wait outside.
Video Intercom System for Home Security
A video intercom system is often more reliable than a traditional doorbell. Instead of the sound-only doorbells that only let the recipient hear who's at the door, an intercom allows you to see whose outside as well.
M741MB Intercom Monitor
This Haakili M741MB has a great visual appearance on your wall at home or office you require, audio and video from your front door.
C543KP Intercom Door Station
Suitable for home, villa and commercial office. Outdoor camera with built-in infrared(IR)for night time viewing with keypad entry.
M741W Intercom Monitors
7 inch Colour TFT Touch Screen Monitor. With a single press of the button to turn on the outdoor bell camera from the handset.
C543 Intercom Door Station
With a stylish brushed Aluminium Alloy Front Panel. 420 TV Line Dual Communication. Anti-vandal and weather proof and Flush Mounted.
M-441 Intercom - Monitor
With a 4 Inch Colour Display Monitor with Picture Memory. Records Visitors both Automatically & Manually, With Flush Mounted.
C541KP Intercom Door Station
Stainless Steel front panel, Outdoor camera with built-in infrared(IR) for night time viewing, Suitable for home, villa and commercial office.