Gerson 1840 R95 Particulate Respirator wwith valve, Full Gasket, Adjustable Straps NIOSH R95 provides at least 95% filtration efficiency against solid and liquid aerosols, including oil based aerosols. Time use limitations apply. Full foam inner gasket helps provide a good seal and is comfortable to wear. Adjustable head straps. Premium oversized valve opens more easily to expel hot air for cool comfort.