Dear customers, welcome to our store! Cycling Filter Mask : ★Description: Total length: 52.5cm/20.66"(approx) Max height: 13cm/5.11"(approx) ★Features: ✔100% Brand new and high quality. ✔Material soft, comfortable wearing, feel is good, dustproof, thermal effect is very good. ✔According to the person face design, keep out the bridge of the nose the following part, the bridge of the nose department have aluminum sheet fixed, to prevent the slide. ✔Mouth have ventilation holes, the magic stick fixed. ✔With activated charcoal filter, filters out exhaust emissions fastening. ✔Suitable for doing activities like biking, riding, snowboarding, or climbing. ★Features: ✔The filter element of this mask has 4 layers of protection, bringing you a safe breathing experience ✔Special 4-layer activated carbon filter can effectively filter PM2.5 haze, dust and other fine particles ✔Prevent second-hand smoke and automobile exhaust. The filter cannot be cleaned. It is recommended to replace it once a week ★Specifications: Anti haze and dustproof square arc active carbon filter active carbon PM2.5 mask filter Weight:40g each pc Size: One Size Material: Activated carbon Package Includes: 1 mask