Sold as 1 Each. PCI express. Antenna configuration: 2x2:2 (TxR:S), industry standards: IEEE 802.11b. Supported protocols: CSMA/CA, full duplex support, modulation: OFDM/DSSS/DBPSK/DQPSK/CCK. Backward compatible with IEEE 802.11b/g standards for up to 11/54 Mbps connections respectively with wireless-B and wireless-G networks. Certifications Standards: IEEE 802.11b, 802.11g, 802.11n, FCC, CE. 300 Mbps. Connector type: 2 - RP-SMA (coax, reverse polarity subminiature A) female. LED indicators: 1 - link/activity (green). Support for WMM/WMM-PS quality of service (QoS), dual detachable 2dBi antennas. Warranty: 2 years limited. Network adapter wireless security: WEP 64-128-bit, WPA, WPA2, WPS, TKIP, AES. Bandwidth: 20/40 MHz, Frequency range: 2.4 - 2.484 GHz, Maximum data transfer rate: 802.11n: 300 Mbps. Operating temperature: 14 - 158 deg F. System requirements: Windows XP(64 bit)/Server 2003(32/64 bit)/Server 2008 R2/Vista(32/64 bit)/7(32/64 bit)/8(32/64 bit), Linux 2.6.32 or later. Interface: Wireless Ethernet, Bus type: PCI express, Card type: standard profile. Form factor: Internal. 2 transmitter/2 receiver (2x2:2) antenna configuration, compliant with IEEE 802.11n standard, with support for up to 300 Mbps of wireless data bandwidth. Package contents: PCI express wireless networking card, antenna, low profile bracket, driver CD, instruction manual.