The Federal Signal Model 300VSC-1 SelecTone® Command Unit generates up to four tones or voice communications in a SelecTone System. Four tones, auxiliary, test and cancel are controlled via an illuminated keypad. Voice transmission is activated by keying the optional desktop or hand-held microphone. Select up to four plug-in tone modules, including the UTM Universal Tone Module and the TM33 Custom Tone Module. Public address can be accessed from the local microphone or via the remote microphone input. Audio input allows background music to be played from any 1 volt-peak-to-peak source system. Public address has the highest priority followed by tones 1-4, remote microphone and auxiliary audio. "Test" plays tones or voice messages through the monitor speaker only. "Cancel" interrupts any tone. External switches can be wired into the command unit for automatic remote operation of the signal system. The 300VSC-1 SelecTone Command Unit is the basis for a simple, versatile general signaling system for weather warning, start and dismissal, general alarm, evacuation and paging.