This mask is designed with a foam strip to prevent fogging of eyewear during use. Tie back style enables tighter fit to suit users. Mask meets AS 4381:2015 for level 3 barrier, Bacterial Filtration Efficiency (BFE) = 98%, Differential Pressure (Delta P) 5.0 mm H20/cm3, Fluid Resistance: 160mm Hg. Mask is for non-therapeutic use.