The Units option lets you view the conversion factor (scaling value) the plug-in uses as well as modify the conversion units.

This option automatically identifies, sets, and converts units of the incoming file to match units of the host application.

If this option is active, but the File Units match the system units, there is no need for scale conversion and the plug-in applies no conversion. The displayed Scale Factor is 1.0 in this case.

NoteThis conversion affects only incoming data. This conversion does not change the settings in Maya.