Hello Roberto,
the list of supported optics is in the GBIC compatibility matrix table 8, the type of fiber depends on the GBIC, the module has slots for GBIC
http://www.cisco.com/en/US/docs/interfaces_modules/transceiver_modules/compatibility/matrix/OL_6981.html#wp142660
The supported part numbers are:
WS-G5483
WS-G5484
WS-G5486
WS-G5487
CWDM GBIC
That correspond to the following descriptions:
WS-G5487
1000BASE-ZX GBIC (single mode only)
WS-G5486
1000BASE-LX/LH GBIC (single mode or multimode)
WS-G5484
1000BASE-SX GBIC (multimode only)
WS-G5483=
1000BASE-T GBIC
see
table 1 of the same document
http://www.cisco.com/en/US/docs/interfaces_modules/transceiver_modules/compatibility/matrix/OL_6981.html#wp142660
DWDM GBIC
So summing up the WS-G5484 is for multimode fiber only and the WS-G5486 for single mode
Hope to help
Giuseppe