Smart Air Filters produces an indoor air purifier that is highly effective against PM 2.5, the primary air pollutant affecting urban Indian cities.” “Smart Air's do-it-yourself filters are available for 3,399 rupees – a fraction of the cost of conventional models on the market.Smart Air is a social enterprise dedicated to fixing the injustice in the air pollution industry. We do this by educating people about the harms of air pollution and providing effective yet affordable solutions for clean air.