Bell wire
Bell wire is laid as signal line between signal transmitter (e.g. a pushbutton) and signal receiver (e.g. chime).
The cable can be laid on the wall surface (surface-mounting), in the plaster layer (impulse installation) or under the plaster layer (flush-mounting) in the masonry.
The bell wire can be laid in an installation pipe for better protection.
The wires are marked with different colours.