Valcom V-2904
Valcom V-2904 Intercom, Door Answering Device, 4 Doors, 10dBm; Alarm functions, Transmit and receive volume control- Background music input with volume control, Built-in ring generator with on/off switch, 3 Distinctive ring patterns, Programmable options include door unlock codes, Places simultaneous calls in queue, Requires -24 Vdc- 600 mA (filtered) 10 Vac lamp, Input impedance: 600 ohm, Ouput impedance: 45 ohm, Music input 4 to 600 ohms, Power requirement: -24 Vdc- 600 mA.