2 wire, audio, wall mount handset includes a door lock release pushbutton and a pushbutton that can be configured for auxiliary functions.

2 WIRE handset that CANNOT be fitted with accessories, wall mounted installation
Door lock release pushbutton, and a pushbutton that can be configured for auxiliary functions (staircase lights switching on, activation of the entrance panel, call to the switchboard)
Bell volume can be adjusted to three different levels