Clear-Com/RTS System Interface Rack Mount (1RU), connects Clear-Com to Clear-Com or Clear-Com to RTS systems TW-12C connects a single channel of intercom from one system to another. Opt isolation eliminates hums and buzzes. Compensates for level and impedance differences between systems. Allows Clear-Com-to-Clear-Com, Clear-Com-to-RTS, and RTS-to-RTS system configurations. Powered by the connected intercom system. Translates "call" signals in both directions.