"RT-SMA" stands for "Reverse-Thread Sub-Minature type A". [RTSMAConnector RT-SMA Connectors] are the cousins of [SMAConnector SMA-Connectors], and provide identical performance.

Reverse-Thread connectors differ only by the direction of the threading of the outer 'ground' contact used to hold connectors together. In [RTSMAConnector RT-SMAs], the thread is "left-handed", and therefore to create a connection you lock the connector in a counter-clockwise direction instead of the normal clockwise direction.

Reverse-Thread connectors are used on [802.11] gear due to America's [FCC] requirements (Part 15.203) where by such equipment needs non-standard connectors. Other modified [SMAConnector SMA] solutions to satisfy the [FCC] requirements are to either use "[RPSMAConnector reverse-polarity]" or "[ShroudedSMAConnector shrouded]" connectors.