KN95 MASK WITH RESPIRATOR the exhalation valve reduces heat build-up and exhalation resistance inside the respirator to make it easier to breathe and help keep the wearer more comfortable. Perfect for traveling through busy, public environments such as malls, markets, offices, public transportation, and more. The idea is for both indoors and outdoors. Bacteria and dust filtration efficiency is ≥ 95%: made of quality activated carbon, non-woven, and melt-blown filter cloth, which effectively filters out 95% of bacteria, exhaust, pollen, smoke, dust, chemicals, particles, and fumes.