OS6900-X20: 10Gigabit Ethernet L3 fixed configuration chassis in a 1U form factor with 20 SFP+ ports. one optional module slot. Rear to front cooling. The chassis includes a modular DC power supply. A second power supply slot is supported for redundancy. Redundant power supply shall be ordered separately. The OS6900-X20 ships with user manuals access card. rack mounts. and USB to RJ-45 adaptor.