Oksale&reg; Ultra Silent Mini 3W 1.5W High Energy Efficient Adjustable Aquarium Fish Tank Oxygen Air Pump Increase oxygen levels, lower CO2 and raise pH It is an important instrument to successfully keep aquatic fish for respiration process High output, Ultra quiet, Energy efficient, Durable Out of gas: 1.2L / min ,2.5L/min Voltage :220-240v