Specification Available Ship to:United StatesDetails Features *Activated carbon filter traps and filters air molecules, dust, chemicals, particles, pollen and smoke. *Perfect for outdoor sports and activities such as cycling, Motorsports, running, skiing, paintball, commuting, and lawn mowing. *Comfortable seal for most adults. Breathable elastic nylon mask, adjustable memory metal nose piece, Tighten and loosen nose piece as needed. Large Velcro headband and ear loop straps,  One size fits all with hoop & loop tape to adjust the fitness. *Two exhaust valves reduce airflow resistance, heat and humidity. Stays cool and dry for long periods of use, exercise, and hot weather use. *Upgraded exhaust valves are more durable, seal better, easier to install, and can't accidentally open or lose the silicone exhaust flap. *Each filter lasts 3-30 days depending on pollution level. Nylon mesh mask can be washed and lasts 1-2 years of daily use.   Filter Replacement Instructions 1. Replace filters after 3-30 days of use depending on pollution level or when the inner layer turns grey. 2. Rotate exhaust valves counterclockwise to unlock. Remove the valves and filter. 3. If washing, soak mask and valves in warm water and detergent. Rinse and air dry. 4. Insert inner valve pieces into the mask and stretch new filters over the valves. Rotate outer valve pieces clockwise to lock.   Specifications Mask materials: Nylon spandex and polyester Velcro mask. Plastic exhaust valves and plastic and metal nose piece. Filter layers: 2x Waterproof nonwoven polypropylene, anti-odor activated carbon, cotton prefilter, and electrostatic meltblown cotton submicron filter. Department: Unisex Adults Net weight: 1.5 ounces (43 g) for one mask and filter. Size: One size fits all with hoop & loop tape to adjust the fitness. Size: 14' length by 6' height. Velcro strap circumference of 28' (26" without stretching). Comfortably fits 20" to 25' head circumferences.  Suitable for cycling, climbing, running, outdoor sports, etc.   Package Include 1 / 2 x Half Face Mask 2 / 4  x Replacement Exhaust Valves 6 / 12 x Replacement Filters