Provides a protected ""safe"" area to help newly added fish or invertebrates acclimating to their new home. Provides a place for injured fish or corals to regenerate damaged tissue without a separate hospital tank. Also functions as a culturing area for small organisms that are intended as a food source for inhabitants of the main aquarium. Includes a Via AquaPowerhead to provide necessary circulation through the refugium at all times.ModelDimensionMedium7 1/4"" x 4"" x 9 1/2""Large12"" x 6"" x 8""