Canon LBP3360 User Manual page 106

2
When changing the size of the paper to be loaded, change the
positions of the paper guides.
● While holding the lock release lever of the side paper guides, slide
the guides to the mark for the size of the paper to be loaded.
The side paper guides move together. Align the position of (A) with the mark for
the size of the paper to be loaded.
(A)
4
NOTE
If you are using B5 size paper (182 mm x 257 mm), set the paper guide to "JIS B5".
Printing from the Paper Cassette 4-23