NANO FIBER MASK with rubber bands 20pcsUnique medical mask brand Batist Czech production with a nanofiber filter. Industry leading filtration efficiency against bacteria (BFE) of 99. 8% and against viruses (VFE) of 99. 8%. Universal size. Popular with professionals firefighters, policemen and paramedics, suitable for real protection even in ordinary civilian life. While a conventional face mask prevents the spread of infection from the wearer to people around him, this top of the line nano