![Canon EF 400mm f/2.8L IS II USM Instructions Manual Download Page 25](http://html1.mh-extra.com/html/canon/ef-400mm-f-2-8l-is-ii-usm/ef-400mm-f-2-8l-is-ii-usm_instructions-manual_3056502025.webp)
ENG-24
17. Drop-In Filters
Detaching Drop-In Filters
To detach a drop-in filter, press in both lock
buttons and pull the filter holder straight out of
the slot.
Attaching Drop-In Filters
To attach a drop-in filter, push the filter holder
straight down into the slot until it clicks into
place. The filter holder can be attached facing
either forwards or backwards.
A Drop-In Screw-Type Filter Holder 52(WIII) and
Canon PROTECT filter are included with the
lens.
Before using a commercially available lens filter,
first detach the PROTECT filter. The filter size is
52 mm, and only one filter can be used.
PROTECT filter
Lock buttons
Drop-In Screw-Type Filter
Holder
A 52(WIII)-series Canon drop-in filter can be used with the lens.