Alfie Pet by Petoga Couture - Johnson Hang-on Nursery Fish Tank with Isolation Breeding Hatchery - Size: Small Dimension: 4" long; 4.25" wide and 5.75" high. Ideal as maturation tank for fry, or isolation tank for aggressive or injured fish. Removable dual-V-shape center partition provides maximum protection and allows two pregnant fish to be safely isolated. Space saving design that hangs on the inside of the aquarium. Easy to assemble and please remove the protection film before use.