This item appears to be a frosted glass box, about 6 inches in size. Once per long rest, when the Frigid Cube comes in contact with water, it will turn the surface of the water into a layer of ice, expanding out to Close range. The icy layer is no more than 3 inches in thickness. The Frigid Cube can be lifted off the ice at any time, but will not slide on the icy surface. Once the Frigid Cube is no longer in contact with the ice, the ice layer immediately melts back into water.