Optional interface board for up to four analog telephones or other telephony devices, allowing Mercury subscribers to make and receive calls anywhere on the system.

Optional interface board for Mercury hardware panels and third-party telephony systems, like PSTN lines, PBXs, cellular telephone interfaces and other telephony devices.

Optional interface board for up to eight full duplex and/or half duplex radios from a wide range of manufacturers.

Optional interface board for Mercury hardware panels and analog audio inputs and outputs. Once an AEB interface is added, hardware panels can be connected to enable seamless voice communication between the panels and any other Mercury operator. Optionally, connected analog voice circuits can be made accessible to any device throughout the Mercury system.