The Marina 50 air pump combines high performance output with quiet operation. It maintains a reliable source of air flow for increasing water movement & turbulence for proper oxygenation, & can also be used to operate items such as air stones, air curtains & air-actuated ornaments. Marina 50 has a single outlet & is ideal for aquariums 5 to 15 U.S. gal. (10 to 60 L)