Canon BJ-20 User Manual page 56

Notes
Remove the envelope manually if it is not ejected after printing.
When using the auto sheet feeder, the REV ADJ Switch is not
available.
Specifications
Size: 310.0 X 217.5 X 57.5mm (12.2" X 8.6" X 2.3")
Weight: Approx. 1.3kg (2.9 lbs)
Bin Capacity:
50 sheets of paper maximum - at 64 g/m
Paper sizes: Letter, legal, A4, B5, Envelopes
Paper weight:
64 to 90 g/m
2
(17 to 24 lbs)
2
(17 lbs)