MicroMall 6 inch duct fan with fuselage knob speed regulation regulationAn inline duct fan with flexible speed control designed to quietly ventilate hydroponic grow rooms, boost heating/cooling to rooms, circulate fresh air, exhaust projects, and cool AV closets.Featuring an inline mixed-flow design, the duct fan can maintain airflow even in high static pressure applications. Contains an EC-motor with PWM-control for a quiet and energy-efficient performance.Complete kit includes one duct fan unit, AC power plug, variable speed controller,two conduit clamps and required installation hardware.100% controllable silent EC motorThe fan body integrates a 0-100% variable speed dial, which is a continuously variable dial controller, allowing you to select any speed without any hum or noise.Compared with AC fans, its power is reduced by 40-75%, thus providing unprecedented airflow.These motors are controlled by a computer chip on the board, allowing precise speed adjustment without wasting energy and heat.Quiet and Energy Efficient DesignFeatures an EC-motor that is controlled using PWM (Pulse Width Modulation). This technology enables motors to be able to run smoothly at extremely low RPM speeds without generating additional heat or noise.In addition, the duct fan uses a mixed- flow design using a stator blade and dual hydrodynamic wind circles. This gives it a high static pressure rating, enabling it to deliver airflow even in applications where air movement is being restricted.The motor houses dual ball bearings rated at 67,000 hours which allows the duct fan unit to be mounted in any direction.The unit is IP44 rated to be highly resistant to dust and liquids, and performs well even in harsh environments.