30mg/hr Ozone Fresh Air Machine is excellent for cellars, cigarette smoke, bathrooms, pet areas, refrigerators, etc. Low cost forced air system produces over 30 mg/hr of air purifying ozone. The operating sound level is very quiet at about 30db, with only the running fan making a noise. Unit can be left running continually to eliminate odors, or just long enough to provide that fresh air outside smell. Operates from 12 vdc (runs on 115 vac with included wall adapter), using about 11 watts of power. Size: 4 x 3.5 x 3" and weighs about 11 ounces.