Fresh air is a crucial component for a healthy harvest. Growing plants transpire water vapor and moisture in the grow room which can cause high humidity that can stunt your plants and destroying your crop. Our Hydro Crunch Booster Fan can help you to maintain a healthy grow room by efficiently move large volumes of air throughout your ventilation system. For high-powered ventilation and noise reduction, our inline booster fan runs 50% quieter than leading competitors. Contents of the combo: 6" Hydro Crunch Booster Fan, Hydro Crunch 6" x 12" Virgin Carbon Filter, 6" x 25' Non-Insulated Air Duct, 25 ft. long.