BKL Electrical SMA Adaptors/Connectors to SMA Connector/Adaptors/Couplers/Socket – BKL 409073, The SMA Adaptor to SMA Coupler is a standard SMA (Sub-Miniature-A) coupler to SMA coupler is used mainly for applications in the frequency ranges 1GHz to 18/26.5 GHz (depending upon the design). The plug connector is considered as male and the socket as female, depending upon the design of the inner conductor as metallic pin or as metallic pipe. It has a high mechanical strength owing to the screw lock (8mm). BKL 409073 SMA Adaptor SMA Coupler to SMA Coupler