Antibacterial Filter for Cosmed Respiratory and Metabolic devices. These filters are compatible with all Cosmed Spirometers. The big advantage of using a filter over a standard cardboard mouthpiece is that it is hygienic for both the patient and also the healthcare practitioner. Cardboard mouthpieces risk contaminating both the device and room the procedure is being performed. This single use antibacterial filter is the safe choice - Quantity: 50 / Box.