SMA

The SMA connector holds a single fiber. SMA connectors have a threaded coupling nut.  The ferrule is traditionally made of steel, although ceramic versions are available.  SMA connectors come in two varieties: the SMA-905 has a straight ferrule, whereas the SMA-906 has a step-down nose.  Both types of SMA connector, the 905 and the 906, are standardized by both NATO and the IEC.