This VIVOSUN 6-inch inline booster duct fan is listed in new condition and includes a speed controller for adjustable airflow in HVAC and ventilation setups. The 345 CFM rating may help shoppers compare it with other duct fans for grow rooms, home ventilation, or other air-moving applications where an inline fan is needed. Free shipping is included, which can be useful when considering total cost. If you are matching an existing system, the 6-inch size is an important buying note to confirm before purchase. This item may suit buyers replacing a similar fan or building out a ducted ventilation setup. Check the listing for full details. VIVOSUN 6" 345CFM Inline Booster Duct Fan HVAC Ventilation w/ Speed Controller. Color: Black, Condition: New. Listed at 36.99 USD. High Efficiency: Equipped with an upgraded EC motor for powerful performance with low energy consumption, extended service life, and reduced maintenance costs.High Efficiency: Equipped with an upgraded EC motor for powerful performance with low energy consumption, extended service life, and reduced maintenance costs.