MJ-1 Core

MJ-1 Core is a premium core-slot droid armor. It can be obtained by Jedi Knights as a mission reward for completion of the level 29 mission Siege Mentality, on the planet Alderaan.

Source
MJ-1 Core is a mission reward obtained by completing Siege Mentality, a level 29 mission obtained on the planet Alderaan.
 * Mission reward