Product DescriptionThe intercom system card is an add on module used to expand the functions of a master station in an audio communication system. It allows the master station to support additional rooms doors or sub stations without changing the main unit. The card installs inside the master station in a dedicated slot which keeps the wiring neat and the setup clean. Once installed it helps provide clear communication between stations and supports features such as call signaling room selection and door control depending on the system design. This card is useful in homes offices small buildings and other locations where the intercom system needs more coverage or more points of communication while keeping the installation simple and reliable.