Clear-Guard Viral and Bacterial Filter with MouthpieceProduct overview Antiviral breathing filter To avoid cross infection Filter and mouthpiece in one unit Filters 99. 99% of bacteria, viruses and fungi Pack with 50 pieces Clear Guard Viral and Bacterial Filter with Mouthpiece Clear Guard Viral and Bacterial Filter with Mouthpiece from Intersurgical provide a high level of protection against infection transmission. The breathing filters are attached to the patient connection, expiration port or