Agilent Technologies 1660A Series User Reference page 381

Ferrite Installation Instructions
Use the following steps to install the ferrite on the logic analyzer cable.
Place the ferrite halves and spacer on the logic analyzer cable like a
1
clamshell around the whole cable. The ferrite should be 10 cm
(about 4 in) from the the end of the cable shell as shown.
Insert the clamps onto the ends of the ferrites. The locking tab
2
should fit cleanly in the ferrite grooves.
When properly installed, the ferrite should appear on the logic analyzer cable
as shown.
Operator's Service
Ferrites (1664A Only)
20-5