Features inner foam for a custom seal, while a dual head strap provides optimum fit. Effective against particulate aerosols free of oil. Helps provide comfortable, reliable worker protection against certain non-oil based particles in work applications including grinding, sanding, sweeping, bagging and other dusty operations. Model 8611 features an exhalation valve to reduce hot air build-up and keep workers cool. NIOSH Approved. 12 Boxes/Case.