Features: 1) USB2.0 supported 2) Support SIP, H.323, MGCP 3) Support Skype, MSN, Xpro, Net2phoneX-pro, X-lite, eyeBeam, Firefly, SJ phone, StanaPhone 4) Easy to use like mobile phone 5) 16 bit USB sound card inside 6) No USB driver needed for Win 98 SE / Win Me / Win 2000 / Win XP/ Mac OS 7) Echo cancellation, noise reduction, and full duplex communication 8) Adjustable volume for handset and ring 9) PC-to-PC and PC-to-phone operation 10) Phone rings for all incoming calls