Features Floating 600 ohm output Selectable 12V DC talk battery for interfacing with C.O. ports Paging port interface Ringing analog line input for night bell Contact closure input for night bell Normally open and normally closed VOX activated contacts for cutting out background music Adjustable VOX contact time-out Adjustable ring volume Specifications Power: 120V AC/12V DC 500mA, UL listed adapter provided Dimensions: 133mm x 89mm x 44mm (5.25" x 3.5" x 1.75") Environmental: 0 degC to 32 degC (32 degF to 90 degF) with 5% to 95% noncondensing humidity Relay Contacts: 30V DC@1A, 110V DC@0.3A, 125V AC @0.5 Maximum Ring Output: 490mV AC RMS no load, 150mV AC RMS@600 ohms VOX Minimum Audio Signal to Activate Relay: 50mV AC RMS@1K Hz Talk Battery: 12V DC