FeaturesP-series filter intended for removal of any particle including oil based liquid aerosolsP-series filters should be used and reused for no more than 40 hr of use or 30 daysLightweight and easy to breathe throughAt least 95% filter efficient when tested with -0.3 um DOP (Dioctyl Phthalate) aerosolThis filter is for comfort, versatile protection, simplicity and has effective durability