Cooling Fans 4 fan unit

Powerful cooling fans increase air movement to reduce heat and humidity Easy-to-install cooling fans perfect for ventilating aquarium sump area Minimizes unwanted water temperature increase due to aquarium equipment Large cooling fans provide powerful ventilation to reduce heat transference from aquarium equipment. Extremely quiet operation with adjustable positioning, perfect for sumps or for use in aquarium stands/cabinets to reduce humidity. Generates 10 times more cooling power than conventional fans to reduce temperature buildup by 5 to 7 degrees Fahrenheit. Easy to install - simply attach using screw-mounting brackets. High-quality plastic construction. 12V UL-Listed. Model Air Flow (CFM)DimensionsRecommended up to 2 Fan Unit 31.57 7-3/4" x 4-3/4" 21 gallons4 Fan Unit 38.5614" x 4-3/4" 42 gallonsPlease click on "More Information" for ventilation tips.