This box has 15 small grid boxes inside. The internal grid can not be moved or dismantled. It is fixed. Can be used it to hold small-sized components such as resistances, buttons, LED etc.. The blue button lock on the surface of the box is used to keep the inside things safe. The surface is water-proof because the major material of this box is plastic. But you can not dip the box into water for the box is not seamless and the water will immerse it.