These masks are intended to be used for protection against solid and liquid aerosols in wood, cement glass working, textile, mining and construction environments. They are extremely durable and they have a soft and comfortable inner surface with an adjustable nose piece and secure head straps for a proper fit. All FFP1&KS2 masks are to be used in situations up to 4 times the Occupational Exposure Level (OEL). The exhalation valve reduces breathing resistance and provides greater comfort in hot and humid work conditions.