PC-to-PC and PC-to-phone mode Clear sound quality and effective echo/noise elimination Driver built-in, plug and play No sound card and external power supply required Complies with H.323, MGCP, SIP protocol Application supports: Skype, Netmeeting/Messenger, Sjphone, Mediaring, Net2phone, Dialpad, Etalk, X-PRO, X-PRO Vonage, Firefly, and Eyebeam Full duplex communication Support Skype speed-dialing function