The Urban Mask Filter is tested with equivalent results of the American N95 or European FFP2 performance (Test: GB2828 & Certification: KN95) Replaceable Active Carbon Filter protects user from vehicle fumes, hydrocarbon gases and reduces odor. Metro Mask: URBAN is the new generation advanced air pollution mask that filters up to 99% of dust and pollutants in the air. Metro-Mask: URBAN is very effective, durable and at the same time very comfortable to wear. Frequently Asked Qustions: 1.WHAT CAN METRO MASK FILTER OUT ? - Equipped with advanced electrostatic, micro-fiber and active carbon filtration technology. The Metro-Mask: Urban is designed to protect against the following particles. - [x] AIR POLLUTANTS (INCLUDING PM10, PM2.5) - [x] POLLEN - [x] BACTERIA AND VIRUSES - [x] SMOG - [x] Automobile exhaust and smoke - [x] Odor and fragrance - [x] Animal Allergens. 2. HOW LONG CAN I USE ONE FILTER ? - The working life of a filter depends on many factors such as the pollution level in your surroundings. On average our filters last 60 to 80 hours. If you use it approximately 2hr everyday in Kathmandu's condition we advise to change every third week for hygienic reasons. 3. CAN I WASH THE FILTER ? - The filter can NOT be washed. The filter ifsoaked in water isdamaged and the filtering efficiency will be reduced. 4. CAN I WASH THE MAIN MASK ? - Yes, you can hand wash the main mask with a little mild detergent. Detach the filter and the valves before washing. Do not store it in a bag unless fully dried. 5. HOW DO I GET THE RIGHT TYPE OF FILTER AND SIZE ? - Each design of mask has it's own type of filter. Please check the size of the mask on the care label to find the correct size and correct type of filter for your mask and then order accordinly. Brand Metro-Mask SKU 100656307_NP-1021090347 Model URBAN Filter Pack ( 2 Replaceable Active Carbon Filters )