The VIVOSUN R6 6 Inch 390 CFM Inline Duct Fan is a versatile ventilation solution suitable for both indoor and outdoor use. With a variable speed controller, adjustable height, and thermostat, this exhaust fan allows for precise control over airflow to keep your space cool and comfortable. Its compact size and powerful 390 CFM output make it perfect for use in hydroponics systems, greenhouses, and other outdoor spaces. The fan's sleek black and red design adds a stylish touch to any environment. Powered by USB, battery, or electric sources, this fan is a reliable choice for all your ventilation needs.