US Robotics USR 56K USB Faxmodem. Modem speed: 56 Kbit/s, Interface: USB 2.0, Form factor: External. Supported data transfer rates: 56K, 48K, 31.2K, Upstream data rate: 0.048 Mbit/s, Downstream data rate: 0.056 Mbit/s. Compliance industry standards: V.92, V.90, V.34, V.32bis, V.32, V.22bis, V.22, V.23, V.21. Minimum system requirements: 5 MB HDD USB Analogue phone line 2x CD-ROM, Minimum processor: Intel Pentium III 600 MHz, Minimum RAM: 128 MB. Dimensions (WxDxH): 98.6 x 38.1 x 22.4 mm, Weight: 0.12 kg