For use in the home or commercial.
See and hear who is at the door (popular with the elderly)
Video or Audio systems.
Flat screen- modern colour designs options
Talk and see them via telephone sytem/intercom
Can be adapted to unlock doors at the touch of a button if required- to gain your visitor entry.
Gate entry systems
Phone ringing systems - the phone in your house rings when caller presses a button, instead of having a separate system
Proximity detection systems - use a keyfob, code or swip card to gain access to areas- can be computer controlled systems for larger organisations