This aquarium cooling fan is able to reduce water temperature and lower by up to 2~4°C, meeting the daily use of aquariums. There are 1-6 head fans for you to choose based on your demands. Features: ❄ Two-speed wind control: Depending on the indoor temperature, the cooling fan is able to reduce the water temperature and drop by up to 2~4°C. (The 5-head fan and the 6-head fan have only one gear) ❄ Easy to use: This fan can be directly attached to the aquarium glass which is 15mm thick, no method no additional installation is required and it is very convenient to use. ❄ Adjustable Fan Head: Adjustable brackets allow 45 degree head movement. You can control the airflow direction according to your needs. ❄ Safe and Convenient: Excellent 12V cooling fan safety voltage, with high safety standards, and ensure fan safety. It responds to the daily use of aquariums. ❄ Multiple Types Optional: There are 1-6 head fans for you to choose based on your demands. ❄After-sales service guarantee: Any