feature: pc-to-pc and pc-to-phone operation driver built-in, no need addtional driver usb1.1 compatible, no need sound card. no external power requiredcomplies with h.323, mgcp, sip protocol caller id function of voip calls 199 incoming call and 199 dialed number latest vogue of of the cellular phone type design, the hand feeling good, three kinds of color choice ( gray, silvery, red) with lcd and led show echo cancellation, noise reduction full duplex communication application support: netmeeting /messenger, mediaring, net2phone, dialpad customized hand phone casing designs available hardware: no external power required usb power led indicator driver and sound card built-in interface: 1 usb interface to pc danny@vnetphone.com www.vnetphone.com skype id: cnwxdkj