EXFO FTB-500 - Manual (Page 65)

Getting Started with Your Unit
FTB-500 57
Securing your Unit Using the Kensington Lock
Securing your Unit Using the Kensington Lock
Your unit is equipped with a security slot to which you can connect an
optional Kensington lock (security cable) to help prevent theft.
To secure your unit:
Connect your lock to the security slot located at the back of your unit.
Four-slot model Eight-slot model