Epson SQ-2550 User Manual page 150

Note: If you plan to switch between cut sheet feeder use and
continuous paper, load continuous paper as described in
Chapter 2.
2. Hold the assembled cut sheet feeder in both hands and fit
its notches over the pins of the printer. Then lower the cut
sheet feeder unit onto the printer.
3. Close the printer cover.
The Cut Sheet Feeder
Using Printer Options 5-3