7581P100 Model Code: AD - Price is for 1 Pair (part# 7581P100) This item features: -Cartridge/Filter Combination. -Filtration Grade: P100. Model Code Model Description AAResistance:Ammonia, Chlorine, Chlorine Dioxide, Formaldehyde, Hydrogen Chloride, Hydrogen Fluoride, Methylamine, Sulfur Dioxide, Defender Organic Vapor, Hydrogen Sulfide (Escape) ABResistance:Chlorine, Chlorine Dioxide, Formaldehyde, Hydrogen Chloride, Hydrogen Fluoride, Sulfur Dioxide ACResistance:Chlorine, Chlorine Dioxide, Hydrogen Chloride, Hydrogen Fluoride, Sulfur Dioxide ADResistance:Organic Vapor