Smart Robo is an NPC that can enhance equipment of grade +5 or lower by sacrificing using equipment boxes of the same grade (e.g. Pegasus gear can be enhanced using Pegasus Equipment Boxes. The number of boxes required depends on the grade (+) of the gear you wish to enhance.
If an enhancement succeeds, the equipment boxes are sacrificed, and the equipment gains a random number of levels.
If an enhancement fails, you lose the equipment boxes, but not the equipment.