One of the best and simplest ways to let your little ones learn about the concept of object permanence. The Montessori Discs Post Box requires your child to place a coconut disc in the slot of the post box. Your child will discover the coconut disc 'still exists' once they remove the drawer from the box. This act develops object permanence. The Montessori Discs Post Box develops concentration, fine motor skills including pincer grip and hand-eye coordination.