The SSA324 is a system to system interface. It interconnects voice signals between intercom systems that are otherwise technically incompatible. An optional card makes it possible to pass call-light signals between different system types. The two-wire interface is suitable for balanced (Audiocom) and unbalanced (TecPro, Clear-Com) systems allowing RTS Two-Wire to interface with virtually any party-line systems in use today. The SSA324 may be used free-standing, or rack-mounted. Alternatively it may be fitted in a console.