Two-speed wind control, according to indoor temperature, reduces water temperature and drops up to 2~3°C Adjustable jaws can clamp the wall of the cylinder than the thickness within 1.2cm, meet the daily use of fish tanks Large cooling fans 12V safe voltage, with high safety standards and ensure the safety of the fan Adjustable Angle: Adjustable fan and bracket width up to 100°, convenient and easy to install and move 30-day money back or replacement guarantee. (If you have any questions, pls feel free to contact us) Product Description Description: Large fans provide powerful ventilation to reduce heat transfer from aquarium equipment. Extremely quiet operation with adjustable positioning, perfect for saltwater aquarium (reef and frag tank) and freshwater aquarium. No assembly required, easy and convenient to use. Easy installation (clamp mounting bracket). Low power consumption, adjustable 2 level wind strength. With a DC 12V power adapter Specification: - Type: 2 fans - Fits tank