Cone Style with Valve PFE>95% BFE>95% Ø Three layers, each layer is made ... blown web which resists dust and oil-free particleØ Exhalation valve reduces hot air buildup and easy breath in hot/humid ... head straps for comfortable wearingØ Suitable to textile, mining, construction, electronic, food processing, cement, disintegration, agriculture, farm garden, glass, cleaning, etc ...