To safeguard the Indoor Air Quality of your facilities and to optimize the performance of your vacuum cleaner, change filters once they are half full. Four Level Filtration system provides advanced protection against there introduction of pollutants back into an environment. Has 21% more filtration area than non-pleated filters. Fully laminated inner liner eliminates shredding. Dual layered construction captures fine particles, improving Indoor Air Quality. Intercept microbial treatment helps contain odors and prevent the growth of mold and bacteria.