Proxim Wireless SX3-1021A-US SX3-1021A-US, Stratum X3 5GHz All-purpose Unit (BSU single or SU), MIMO 2x2, 1Gbps, Integrated Dual Pol 10 degree Antenna and 2x RP-SMA connectors, US PoE. Requires SX3-102xA-64SU-UPG License upgrade to operate in full BSU