The SMA to FME cable adapter allows the AUSCB to be used with car mounted UHF antennas, who's antenna coax terminate in a FME fitting.
The cable is a specially selected length of RG174 coax.
A cable adapter is a better choice for use with a handheld, than a direct adapter.
Note: The SMA connector does not need to be done up tight to the radios antenna socket, just to a gentle stop is all that is required.