1External wall-mounted design: Small size, easy to install, does not occupy aquarium space. 2Strong wind power: Rapid cooling, can cool the aquarium by about 3, providing a more comfortable environment for fish. 3Solve high temperature problems: Effectively prevent water quality deterioration, fish discomfort, lack of oxygen and inactivity caused by high temperature. 4Free adjustment: Two levels of wind speed can be adjusted as needed, energy-saving and power-saving. 5Wide range of application: Suitable for mini water bodies below 20L. Features: External wall-mounted design: Small size, easy to install, does not occupy aquarium space. Strong wind power: Rapid cooling, can cool the aquarium by about 3, providing a more comfortable environment for fish. Solve high temperature problems: Effectively prevent water quality deterioration, fish discomfort,lack of oxygen and inactivity caused by high temperature. Free adjustment: Two levels of wind speed can be adjusted as needed, energy-saving and power-saving. Wide range of application: Suitable for mini water bodies below 20L. Specifications: Voltage: DC 5V direct current Power: 3. 8W Application: For mini cylinders water bodies below 20L Size: 12.5*7*3cm / 4.9*2.8*1.2 in Package size: 14*7*7cm / 5.5*2.8*2.8 in Package weight: 146g / 5.1 oz Package list: 1*Aquarium Fan 1*Aquarium Fan