Spider Farmer Ventilation Kit 6 Inch 350 CFM Inline Duct Fan with Temperature Humidity Controller, Carbon Filter 32 Feet Ducting Combo Set Ventilation System for Grow Tents HydroponicsPROGRAMMABLE INLINE FANMixed flow design combined with a EC motor ensure truly energy efficient, with only 50 watts of power but gives a strong airflow up to 350 CFM, very low noise level, only produces 32DB, this 6 exhaust fan is silent. Lightweight ABS blades reduce the airflow resistance, add airflow by 40%. The smart controller has multiple modes for operation, 10 speeds, easy to program and controls the humidity and temperature automatically.