HP LaserJet Enterprise flow M830 Multifunction Printer series - Manual (Page 35)

Load Tray 4 and Tray 5
Tray 4 and Tray 5 support 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.
ENWW Load Tray 4 and Tray 5 25