The PA-15 interfaces with virtually any telephone system to provide 15 watts of paging power - enough to drive fifteen 8-ohm paging horns or speakers The PA-15 provides 36V talk battery for interfacing with an FXO or unused analog line input/trunk port. With the flip of a switch, the unit can connect to a FXS or PABX/Centrex station ring trip port or connect to a 600 ohm paging port. When interfacing with systems that do not provide a paging contact closure, the builtin voice activation (VOX) is in control. After paging, the PA-15 auto disconnects on CPC, busy signal, silence or default disconnect timer (helps prevent accidental paging system lock-up if phone is hung-up incorrectly). The unit will generate adjustable loud ringing from an independent ringing analog FXS / PABX / Centrex station or from a dry contact closure. The PA-15 can provide background music (muted during page) if connected to an external music source.