Bkl electrical sma adaptorsconnectors to sma connectoradaptorscouplerssocket 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 18265 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