Oki C9800 GA User Manual page 18

Additionally, the following optional features are available:
> Additional paper trays for loading a further 530 sheets at
a time to reduce operator intervention, or different paper
stocks for letterhead stationery, alternative paper sizes or
other print media:
> 2nd/3rd Tray (530 sheets each)
> High Capacity Feeder (HCF) (1590 sheets)
NOTE
1. Tray configurations are: Tray 1 only, Tray 1 + 2nd Tray,
Tray 1 + 2nd Tray + 3rd Tray, Tray 1 + HCF, Tray1 + 2nd
Tray + HCF
2. The C9800hdtn already has a High Capacity Feeder
installed and so can only accommodate one additional tray
(to give the maximum total of five).
> Memory Expansion DIMM
> Finisher for stapling or saddle stitching printer output
> Punch unit (to extend Finisher functionality)
> Printer Cabinet
> EFI Color Profiler Kit
> MFP Upgrade Kit (C9800hdn only)
C9800 User's Guide> 18