Description: 3M 8511 Particulate Respirator, with Exhalation Valve, White, 10 Per Box Particulate respirator with exhalation valve.Offers protection when the job requires work around tiny particles.Lightweight, but effective.Adjustable nose clip ensures a more secure seal against the face.At least 95% filtration efficiency.Recommended for grinding, sanding, sweeping and other non-oil based operations.Suited for heat, humidity or long periods of wear.