This compact, surface-mounting, internal video unit with colour screen is made of aluminium and is delivered standard equipped to perform the following functions: allow a conversation with a visitor, produce a different tone for a call at an apartment door, main door or an internal call, switch lights on and off, open doors, adjust the volume and image, switch off the ring tone, activate the camera, indicate a busy signal and call signal with LEDs. The controls consist of 5 function keys and a menu that can be navigated with 3 navigation keys on the side of the device. The functionality of one of the keys can be freely assigned. This programmable key can be set up to either transmit a control function for relay 10-831, allow a parallel call, make an internal call, switch the light on and off, set up a ring-and-enter function, or activate a call redirection command. The communication with the visitor is hands-free.