1. Pc-to-pc and pc-to-phone operation; 2. Driver built-in, plug and play; 3. Usb1.1 compatible; 4. No need sound card; 5. No external power required; 6. Complies with h.323, mgcp, sip protocol; 7. Echo cancellation, noise reduction; 8. Application support: Skype, netmeeting/messenger, sjphone, mediaring, net2phone, dialpad, etalk, x-pro, x-pro vonage, firefly, eyebeam and so on; 9. Full duplex communication; 10. Support skype speed-dialing function; 11. Key-in tone function.