Supports PC-to-PC, PC-to-Phone and Phone-to-Phone. Voice Features: -Built-in sound card and driver - Echo cancellation - Noise reduction - Full duplex communication Physical Features: - Integrated with keypad, ringer, earphone and microphone -Integrated with keypad, ringer, earphone and microphone - 18 keys in all including 6 fixed function keys - USB 2.0 interface and 2 meters cable