These pre-filters are approved by NIOSH (National Institute for Occupational Safety and Health) under the NIOSH 42 CFR 84 respirator certification regulations, to the P95 category.
These long-life pre-filters are at least 95% efficient against oil- and non-oil based contaminants, and are oil-proof so they have no time use limitation.
10 Pre-Filters/pkg.
Only compatible with the SWX00322 cartridge.