That part number is a bundle of:
a Base Nexus 5548UP,
a 16-port Unified Port Expansion Module,
a 48-port Storage License,
and 8 Fibre Channel SFP+ modules.
A good general data sheet for the Nexus 5500 family can be found here:
http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/data_sheet_c78-618603.html