ZyXEL U-90E - 56K Data/Fax Modem. Modem speed: 56 Kbit/s, Form factor: Desktop. Maximum fax transfer rate: 14.4 Kbps. Data link protocols: V.21/Bell, V.22/Bell, V.22bis, V.23, V.32, V.34, V.90. Operating temperature range (T-T): 0 - 40 °C, Operating relative humidity range: 5 - 90 %. LED indicators: AA, CD, DTR