Sealing Cube

This is a specialized ninja tool unique to Maiya Uzumaki. She uses this to seal the animals/beasts she has tamed within it to summon them into battle at a later time. All animals sealed within the cubes have consented to it and are happy to do so. Inside the cubes is another dimension, all cubes are linked to the same dimension. The cubes are relatively small and are pitch black. The four symbols seal is used to seal them.