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 2 x Half Face Mask 4 x Replacement Exhaust Valves 12 x Replacement Filters.