Features: 1. 100% new brand and high quality 2. 220v 3w 5w Aquarium Air Pump Fish Tank Mini Air Compressor. 3. Increase the oxygen in the fish tank. 4. With low power consumption, high efficiency, energy saving, long life, stable performance. Specification: Model: RS290; RS390 Input: AC 220V/ 50Hz (Attention: not suit for United States,Canada ,Japan,Mexico, Certain regions of Brazil etc. ) Power: 3W (Single Outlet), 5W (Double Outlet) Flow Rate: 1.2L / min, 4.5L / min Size: 10.5x5x4.5cm; 10.5x7.5x5cm Plug Specifications: EU Plug/US Plug/UK Plug How to use it: 1.The voltage and the frequency of the air feed pump using must be meet requirements 2.The position of placing the air pump must be higher than that of the aquarium, which can avoid the water flowing into the inside place of the machine following the exhaust pipe 3.Connect the gas piping to the air outlet of the air pump, the uniformly distribute the vesicle stone in the aquarium, switch on power supply and the air pump will be air-entrapping and oxygenation 4.You can choose single air outlet or double air outlet depend on the oxygen demand to reach the ideal air supply and oxygenation 5.The filtration cotton of the air pump and the vesicle stone must be washed and replaced in every three months 6.The air pump should disconnect with the power supply, and placed in the dry environment when do not used Package list: 1* Air Pump or other Other Accessories FREE SHIPPING IS INCLUDED!