I purchased this new on Amazon three days ago. This is an ozone generator that deodorizes various odors, such as pet odors and mold odors. --- This product generates low-concentration ozone (100mg/hour), effectively removing odors while ensuring safety. It has five modes to handle various smells. This ozone generator does not require a filter and is easy to maintain. Furthermore, it has a quiet design, achieving a level of silence that you won't even notice while it's running. Please note: Ozone naturally decomposes into oxygen molecules and atoms within 20 minutes. Please ensure that people and pets are not in the room during use. After deodorizing, open the windows and ventilate for 15-20 minutes.