EXFO FTB-500 - Manual (Page 61)

Getting Started with Your Unit
FTB-500 53
Activating Software Options
6. In the Platform Options tab, use the Browse button to locate the key
file that you want to use.
7. Tap Activate.
The option indicator will turn into a green check mark to confirm that
the option is now active.
8. Tap OK to close the confirmation message, and then Close to exit.
Note: At this point, if you have used a USB key to copy your key file, you can
remove it as it is not required to use your new options.