WEN 3410 3-Speed Remote-Controlled Air Filtration System (300/350/400 CFM) Circulate the air in a 400 square foot room up to 7.5 times per hour Three-speed operation flows air at a rate of 300, 350, or 400 cubic feet per minute Includes a 1-micron filter and a 5-micron pre-filter, both of which can be easily replaced Programmable timer automatically shuts unit off after set number of minutes Remote control allows users to set timer, change speed and power the unit on and off from up to 26 feet away