Filter change, second room19Protective grille20Filter mat21Adapter Filter change interval every 6 months, depending on the degree of soiling.Pull the protective grille forwards.Take out filter mat and replace it.Insert new filter mat into protective grille, then press protective grille into correct position on adapter until it audibly engages. Filter mats ZRF: Pack of 5, filter class G2 in accordance with EN 779, art. no. 0093.0923