After using many N-95 masks I think I can write a comment here and also guide people who want to buy this for pollution and dirt protection.N-95 means this mask, if properly worn blocks at least 95% of very small (0.3 micron) test particles.This gives protection against dust/fume/mist (DFM) . Although my primary usage is in a hospital to prevent airborne infections, it can pretty well be used in extremely polluted cities like Delhi, for example. Compared to other N-95 respirators, I find this one to be soft and snugly fitting due to elastic bands. The lining around the mask fits snugly on nose. It can be used for up to 7 days, but ensure you store it clean, preferably in sunlight. Only drawback of any N-95 mask is rebreathing and suffocation, if worn for long periods. So all in all 3M has provided good quality respirators at this price.