Austin Air B402B1 Bedroom Machine Air Purifier, Medical Grade HEPA Filter, HEGA Carbon Cloth, for Improved Sleep, Black Comprehensive 5 stages of filtration specifically designed for use in the bedroom, developed to improve sleep and reduce various sleep related problems like night time asthma attacks and COPD symptoms True medical grade HEPA filter removes 99.97% of all particles larger than 0.3 microns and 5 stage filter protects against a wide range of indoor air pollutants such as dust, pet dander, pollen, and gases HEGA (High Efficiency Gas Arrestance) carbon cloth provides an extremely large surface area for adsorption of chemicals, gases, viruses and bacteria; over 780 cubic inches of activated carbon and zeolite filtration removes chemicals, gases and odors 3 speed settings for fan; 360 degree intake system draws air into all sides of unit, passing air through a 5 stage filter Reduces night time allergies, asthma attacks, snoring, and helps you sleep better; reduces coughing, wheezing, sneezing, dry mouth, runny nose; strengthens the immune system