Clear-Com FOR-22 4-Wire/2-Way Radio Interface (Dual)The FOR 22 connects two external 4 wire circuits to the matrix. Camera intercoms, two way radios, microwave and satellite links, IFBs, and program audio inputs and outputs are candidates for the FOR 22. The module provides proper impedance matching, transformer isolation and level adjustments between systems. It also supports external relay activation and call sense circuitry. The relays can be controlled separately to add to the frame relay