US Robotics USR5637. Modem speed: 56 Kbit/s, Interface: USB. Minimum system requirements: CD-ROM USB, Minimum processor: Pentium 3, Minimum RAM: 128 MB. Operating temperature range (T-T): 0 - 50 °C, Operating relative humidity range: 20 - 80 %, Storage temperature range (T-T): -20 - 70 °C. Dimensions (WxDxH): 98.6 x 38.1 x 22.4 mm, Weight: 0.12 kg. Package dimensions (WxDxH): 137 x 95 x 153 mm, Package weight: 0.23 kg