Service "MPSB2" has 2 instance(s)?

When I checked status of Listener,lsnrctl status, I got,

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LSNRCTL for 64-bit Windows: Version 11.1.0.7.0 - Production on 21-OCT-2010 10:45:59

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Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=hostname)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for 64-bit Windows: Version 11.1.0.7.0 - Production
Start Date                17-OCT-2010 22:19:31
Uptime                    3 days 12 hr. 26 min. 29 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   \Oracle\Ora11g\MPSv2\network\admin\listener.ora
Listener Log File         d:\oracle\ora11g\diag\tnslsnr\AMPS-PDB\listener\alert\log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=hostname.domain)(PORT=1521)))