Features: The use of food-grade high-quality raw materials, safe, non-toxic, and harmless, men, women, and children can rest assured to wear. The nano-filter has good air permeability and can be used when moving, so it is suitable for people who have high requirements for air permeability. Applicable scene: suitable for dust, pollen, mild to moderate haze, and people with severe rhinitis. Family mixed-size package, each with a pair of S-and M-L sizes, with a built-in filter and an additional two pairs of replacement packages. Easy to carry, equipped with mini storage box, easy to wear at any time when you are away from home, there is no need to worry that there is no place to store it. Specification: Item: Invisible Nasal Filter Material: Silicone,ABS Shape: Narrow; Round Optional Narrow Size: S: 9*15mm; M: 11*16mm; L: 11*19mm Round Size: S: 11*14mm; M: 12*14mm; L: 13*15mm Package Size: 8.5*4.5*4cm / 3.35*1.77*1.57in Package Weight: 28g / 0.99oz Package List: 1 * S Invisible Nasal Filter 1 * M Invisible Nasal Filter 1 * L Invisible Nasal Filter 3 * Replacement Filters 1 * Tweezers