MARS HYDRO 6 INCH INLINE FAN AND CARBON FILTER COMBO WITH SPEED CONTROLLERWith a 6'' inline fan rated for 402CFM, an activated carbon filter with Australian charcoal, and a knob controller applied to allow easy switching and adjustment of the fan speed, the Mars Hydro 6 inch inline duct fan and carbon filter combo provides everything you need to set up the ventilation in a grow tent. A good ventilation setup for grow tents measuring up to 5x5 feet. Package Includes: 6" Inline Duct Fan with a knob Speed Controller, 6" Carbon