The Ultrium Plate is a set of plates drop from the Kloxian Protector in the Kloxian ruins.
there are 3 sets of plates that will give a different attribute in the 3rd slot.
the blue set will have +1 power regeneration in the 3rd slot 4000, 4001, 4002, 4003
the green set will have a +1 hull regeneration attribute in the 3rd slot 4004, 4005, 4006, 4007
the purple set will have a +1 psi regeneration attribute in the 3rd slot 4008, 4009, 4010, 4011