Product Use: Vogmask Chakra N99CV Mask: Salient features of Vogmask Chakra N99CV Mask:Quality management and product safety.Available small, medium, large sizes.N99 filter layer, carbon filter, exhale valve.Filtering textile protects from 99% of airborne particles over .3 microns. Superior protection for PM 2.5 particles in air pollution.Meets NIOSH N99 particle filtration criteria for filter efficiency as stated in 42 CFR Part 84.