Bogen 100 watt wall mounted telephone paging amplifier Inputs for 600 ohm balanced telephone line, Lo Z balanced microphone, and background music Music input RCA jack or screw terminals Integral automatic level control ALC circuit for controlling pages made by persons with varying voice levels and paging techniques Page from telephone and/or microphone Signal activated paging channel automatically mutes background music Adjustable background music muting level during a page Music gradually returns to its normal level after a page Audio Enhancement circuit increases intelligibility, improves perceived loudness with no increase in power , and reduces listener fatigue Separate controls for page volume, music volume, night ringer, music mute, and Audio Enhancement Bass and treble controls Built in night ringer activated by contact closure or by 90V ring signal VOX sensitivity level control eliminates accidental transmission of background noise from a paging telephone Thermal and electronic overload protection Jacks provided for bridging additional TPU amplifiers Brackets are attached to each model for easy wall mounting; the TPU250 can also be rack mounted with included brackets; TPU B models can be rackmounted with RPK82 mounting kit sold separately Peak level indicator lights when amplifier is driven into clipping 120V AC, 60 Hz power source Listed to UL Standard 60065 for U.S. Canada