As paramedics when BRK we repeatedly do with inserts in infectious areas where personal protective equipment is required. A good fit - with no possible lateral outlet or inlet of unfiltered breath is particularly important here. Private I have this mask for work on my pellet heating buy (ash container empty Pellet restock) and have to say that a seal is hardly possible due to the unique shape (duckbill) of the mask. In addition, the upper bending rail is not enough for me to seal the mask fit the nasal area. Therefore, with every breath breathing air flows out instead of the filter mask up and out of the mask. Likewise unfiltered outside air enters here by inhalation. For me, therefore only worth 1 point :-(
