This same number appears with the show version command for the processor board.
Seems odd that they would be the same.
show version
cisco WS-C6506-E (R7000) processor (revision 1.1) with 458752K/65536K bytes of
Processor board ID SAL10489LBW
IDPROM for backplane #0
(FRU is 'Catalyst 6500 6-slot backplane')
OEM String = 'Cisco Systems'
Product Number = 'WS-C6506-E'
Serial Number = 'SAL10489LBW'
