This pack of 2 particulate respirator mask filter replacements is a practical and efficient solution for those who need to replace their filters. The P100 2091 particulate filter has a 99.97% filtration efficiency and is flame and water-resistant. It attaches directly to half-face and full-face respirators, fitting most reusable respirators in the 6000, 7000, and FF-400 series. Sold as a pair, these snap-on filters are easy to replace and provide reliable protection against particulate matter.