An air filter is a device designed to remove solid particles and
molecular pollutants to improve the air quality in a system or
environment. The air filter usually consists of a strong frame
filled with a certain filter medium, which is sealed to prevent
leakage between the frame and the medium. Some filters may also
have a mask-a screen attached to the filter to protect the media
during processing-or a gasket to prevent leakage between the filter
frame and its housing.