HP Color LaserJet Enterprise flow M880 Multifunction Printer series - Manual (Page 39)

Load the 3,500-sheet high-capacity tray
The 3,500-sheet high-capacity tray supports only A4 and Letter-size paper.
1. Open the right and left sides of the tray.
2. On each side, adjust the paper-size lever to the
correct position for the paper you are using.
LTR
A4
ENWW Load the 3,500-sheet high-capacity tray 29