The HP LaserJet 8150 is available in three configurations.

HP LaserJet 8150
The HP 8150 comes standard with 32 MB RAM and two 500-sheet trays.
HP LaserJet 8150 N
The HP 8150N comes standard with 32 MB RAM, an HP JetDirect card for connecting to a network, and two 500-sheet trays.
HP LaserJet 8150 DN
The HP LaserJet 8150DN comes standard with 32 MB RAM, an HP Jet Direct card for connecting to a network, a duplexer, and two 500-sheet trays.

Product Data Sheet -- HP LaserJet 8150 (449 Kb pdf file)
Users Manuals available at HP's website.