HP LaserJet 8000, 8000 N, 8000 DN, and HP Mopier 240 Printers User Guide - C4085-60101

Chapter 2 Printing Tasks 102
Printing Both Sides of Paper (Optional Duplex Printing Accessory)
Printing Both Sides of Paper (Optional Duplex
Printing Accessory)
The printer can automatically print on both sides of paper with an optional
duplex printing accessory (duplexer). This is called duplexing.
Note See the documentation included with the duplexer for complete installation
and setup instructions. Duplexing might require additional memory
(page 310).