Universal telephone compatible with most of the telephones produced by the major manufacturers. Ideal in door entry phone system replacements and repairs. Call volume adjustment and privacy. It has a door opener pushbutton and supplementary pushbutton for additional services: up to 8 pushbuttons of which 4 supplementary LEDs can be added, volume adjustment for the microphone and loudspeaker, can be used both for systems with positive common and for systems with negative common, can replace telephones with condenser microphone and carbon capsule, has electronic call or mechanical call by means of buzzer. With this model, Dimensions: 95x215x58 mm