Adtran DSU 56/64. Storage temperature range (T-T): -20 - 70 °C, Operating temperature range (T-T): 0 - 50 °C. Dimensions (WxDxH): 165.1 x 209.55 x 41.275 mm, Weight: 680.3 g. Networking features: 56/64 kbps. Minimum system requirements: RJ-48S, V.35 DDS DTE. Cabling technology: 8-pin_modular