Mini series door-entry phone with handset for Simplebus 1 audio systems. Equipped with a key button, button for additional services such as calls to the porter switchboard..., call volume adjustment, Silent mode (Privacy) and floor call input. Correct positioning of the handset on the base is facilitated by invisible magnetised panels. The additional board art. 2735 is available to purchase separately, for an additional button with voltage free contacts and call repetition.