Canon LBP-2510 User Manual page 26

G Indication of the amount of paper remaining in the cassette
The paper cassette is supported with an indicator that shows the amount of
paper remaining in the cassette. If the cassette is full, the indicator will be at
the top. The indicator will go down as the amount of paper decreases,
therefore, you can acknowledge the amount of paper remaining in the cassette.
Remaining paper
indicator
When a large amount When a small amount
is remaining is remaining
Printing from the Paper Cassette 25