1544000-Clear-Guard 3 breathing filter with luer port The Clear-Guard™ range of breathing filters includes a number of options. They have been designed for use in breathing and anaesthetic systems for the protection of the patient, hospital personnel and the equipment from potential microbial contamination. The Intersurgical breathing filters provide an effective barrier against the passage of Middle East Respiratory Syndrome-Corona viruses (MERS CoV) in respiratory breathing systems