Epson AcuLaser MX20DNF - Manual (Page 37)

Standard paper cassette
This cassette gives you a second paper source in addition to the MP tray.
1. Pull the paper cassette out from the printer.
2. Pinch the tab and slide the paper guides to the size of paper.
Note:
When the size of the paper that is loaded is bigger than A4, push the release lever and extend the paper
cassette to accommodate the paper.
Epson AcuLaser MX21/MX20 Series User's Guide
Paper Handling 37