HP LaserJet 4050 Printer series - Manual (Page 28)

6 Chapter 1: Printer Basics
EN
Accessories and Supplies
You can increase the capabilities of the printer with optional
accessories and supplies.
Note Use accessories and supplies specifically designed for the printer
to ensure optimum performance.
The printer supports two enhanced input/output (EIO) cards. One
of these is used in the HP LaserJet 4050 N and 4050 TN for the
HP JetDirect 10/100Base-TX print server card. Other accessories
and options are available. For ordering information, see page 8.