The Pentar Device was a doomsday device that used the Force to destroy itself and surrounding galaxies. The exact way it controlled the Force was unknown. The device itself could only be used once and it needed at least six other planets to be able to complete its function. The six original worlds were Coruscant, Hoth, Byss, Tatooine, Thule and Malachor V. Due to some circumstances, Malachor V and Byss were not on the list, but they were replaced by Honoghr and Bastion. The Pentar Device could only be destroyed by a large electro-magnetic pulse; like Darth Gneti's Magnetic Factory, for example.