The Federal Signal Model 300VSC-1044SB SelecTone® Command Unit generates up to four tones or voice communications in a SelecTone system. The housing can be mounted in any standard 19 in equipment rack. 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 or the TM33 Custom Tone Module. Public address can be accessed from the optional local microphone or the remote microphone input. Audio input allows background music to be played from any 1 V peak-to-peak audio source. Public address has the highest priority, followed by tones 1-4, remote microphone and audio. "Test" plays tones or voice messages through the monitor speaker only. "Cancel" interrupts any tone. External dry contact closures can be wired into the command unit for automatic remote operation of the signal system. The 300VSC-1044SB SelecTone Command Unit is the basis for a simple, versatile general signaling system for weather warning, start and dismissal, general alarm, evacuation and paging.