BKL SMA and RP-SMA Connectors 50 Ohm Gold-plated – BKL 409074, BKL Electronics 0409074 SMA plug connecters are used mainly for applications in the frequency ranges 1GHz to 18/26.5GHz (depending upon the design). SMA stands for Sub-Miniature-A. The male SMA connectors have a central pin and an internal thread whilst Reverse SMA (RP-SMA) male connectors have central socket contact and an internal thread. They have a high mechanical strength owing to the 8mm screw lock. BKL 0409074 SMA Female PCB Mount 180° 50 Ohm Gold-plated