An [SMAConnector SMA-Connector] is a [CoaxialCable coaxial cable] connector designed for radio frequencies up to 15 GHz running over 50 Ohm cable. "SMA" stands for "Sub-Minature type A" (there are three types, [SMAConnector SMA], [SMBConnector SMB], and [SMCConnector SMC]). [SMAConnector SMA-Connectors] were designed in the 1960's to military specifications and despite their size are highly durable, and even weather-proof (but not water-proof). Unless you have equipment that is not sold in the United States, it's doubtful you'll find [802.11] gear with these connectors. Instead, you'll find gear with something very similar, called [RPSMAConnector RP-SMA Connectors].