Designed for breeding, isolating or acclimatizing fish or shrimp, the Marina Hang On Breeding Box is a safe & secure nursery for livebearer fish that hangs on the outside of the aquarium to make viewing and maintenance easy. Warm, oxygenated water from main aquarium circulates continuously through the breeding box with the use of an air pump (sold separately), so that fish enjoy the same conditions as the aquarium. Additional heaters or filters not required. Multi-Purpose Safe & secure tank for breeding, isolating or acclimatizing fish Space-saving design, easily installs on the exterior of the aquarium Fish fry slip through the V-shaped separator and are safely segregated from adultsAn air pump (1L/ per minute) and airline tubing are required.(Not included)Measures 16 cm (6 1/3 ) wide and holds 1.2 Liters (0.3 US gal.) of water.