The PetKit Pura Air is designed to target odours at the source decreasing dust and removing odours. This smart odour eliminator uses an infrared thermal system technology to accurately identify when your pet enters the detection range. Following detection, the negative ion generator releases its high activity ions to deactivate bacteria. A high polymer solid air freshener extracted from 20 plants is safe and non-toxic to your pet. The freshener removes odour and refresh air as well as decompose the odour molecules such as nitrogen and hydrogen sulphide, etc. The PetKit odour eliminator runs for up to 6 hours automatically and promotes fresh air day and night. Pura Air comes equipped with 5 filters.