An innovative device utilizes ozone purification technology to purify the air inside your refrigerator. 1. Neutralize stale and foul odors with fresh air inside refrigerators, closets, bathrooms and cars. 2. Very ideal for use in refrigerator to keep the foods fresh for longer time. 3. Kill certain types of bacteria to avoid the growth of mildew. 1. Built-in micro CPU intelligently controls the operation cycle & mode by one touch and indicates with the colored LED. 2. Run for about 90 days on 3 AA batteries. Low voltage indicator reminds you of replacing batteries. 3. No costly filter to replace ever 4. Naturally neutralize odors without any cover-up scents or fragrance. 5. Very elegant and space-saving design. Model number RK-A28 Ozone concentration About 4.0ppm in “High” mode (operates 30 minutes inside a 40L closed container) Effective Range “High” mode <250L “Low” mode <150L Rating Voltage DC4.5V Power Supply 3pcs 1.5V AA-size alkaline batteries Power consumption 0.5 watts Dimensions H116xφ80 mm Weight 0.15kg