The PureFlow 70PRO filter is one of a kind, equipped with a HEPA H14 filter and a second stage carbon filter, which together offer the most advanced filtration technology on the market. This filter only needs to be replaced once a year, although we recommend cleaning it carefully with a vacuum every 3 to 4 months to maintain optimal performance. The PureFlow70 PRO's advanced technology meticulously tracks how long the filter lasts, based on the level of contamination and usage. A timely notification informs you when the filter needs to be replaced, so that your air purifier always operates at maximum efficiency. With the HEPA H14 filter for the finest particles and a high-quality carbon filter for the absorption of odours and gases, the PureFlow70 PRO ensures the best air quality.