56K Black USB Fax Voice Data External V.90 V.92 Modem Compatible with Windows 7 ? Transmission Line: RJ11 Complies with V.17, V.29, and V.27ter Group 3 fax protocol Complies with V.92, V.90 and V.42, V.42bis/MNP5 Protocol supporting Win7 & Windows Vista Up to 56Kbps data download, 48Kbps data upload and 14.4Kbps fax communication