Dell NW147 56K External USB Modem, Compatible Model Number: RD02-D400 Compatible With Any System That Supports USB Connectors, and is running Microsoft Windows XP or Vista Interface Type: USB, Transfer rate: 56Kbps, Transfer Protocol: V.92 Error correction control: Support, Data Compression Protocol: Support Chip: conexant, Fax / protocol: Class 1 and Class 2 Fax speed 14400bps, Video conferencing: V.80