Sport Shield Exhalation Valve Mask With Velcro ClosureUse for all indoor or outdoor sports or high cardio activitiesTwo layer material including outer mesh layer and inner stitched polyester/spandex layer for added secure fit coverageFlexible rubber nose clamp adjustment band ~ Dual exhale valves with changeable PM 2.5 filters Washable*Comes With 3 PM 2.5 Filters and Three Sets of Valves