- Single door answering device- Provides two-way communication (does not provide door unlock capability)- Built-in talkback amplifier- Ring generator- Transmit and receive volume control- Includes a VC-VP-324 power supply- Compatible with all Valcom doorplate speakers- Access: PBX loop starttrunk port electronic or 1A2 line key (line cardrequired) or dedicated single line phone set-Input impedance: 600 ohm- Ouput impedance: 45 ohm- Weight 3.4lbs- Dimensions: 8.25 H x 4.5 W x 2.35 D- VALCOM POWER UNITS (N/