TA Triumph-Adler CLP 4721 - Manual (Page 178)

A-5
Appendix
About the Options
This printer has the following options available to satisfy your printing
requirements. For instructions on installing individual options, refer to the
documentation included with the option. Some options are explained in
the following sections.
Paper Feeder PF-520/ PF-530
(Only 2 stacked paper feeders can
Expansion Memory
(DIMM 128/256/512/1024 MB)
Hard Disk
USB memory
Network Interface Card
IB-23
be used with the printer model 21 ppm)
(Printer model 26 ppm
only)