Stanley Personal Protection N95 Replacement Filters RST-64014 are built to help you reuse your Stanley Personal Protection respirators. These small lab safety spare parts are a rather essential respirator component, since they're the part that actively filters out harmful aerosols and chemical agents. The Stanley Personal Protection N-95 Spare Filters are 95% effective against non-oil particulate aerosols, making them highly effective when combined with cartridges in Stanley Personal Protection lab safety masks. Stanley Personal Protection has included two N95 filters in this combo pack. Keep your respirators working longer with the Stanley Personal Protection N 95 Respirator Filters.