Filtered expiratory circuit - A valve stops additional air intrance during expiration. - A very high retention filter collects all aerosols at the expiration. For administration of Isethionate of Pentamidine. PENTACARINAT® in Pneumocystose prevention and processing : the mouth end-piece has to be held in a tigh way between the lips. Inspiration and expiration are done by the mouth end-piece. The total dosage generally of 6 ml through has to be aerolized. The filter is for a single use and has to be thrown away after the treatment.