This item has been discontinued and replaced by the DP29-SW/IM Door Release/Intercom Module

The DP28IM Intercom Module works in conjunction with the DP28C Doorbell Fon Intercom Controller to allow users to ring the telephones in the home from any other telephone within the home to serve as a local intercom. Doorbell Fon installs using a single pair of wires for power, signalling, control and voice.