Patent ID: 8460423

Claim:
A filter cartridge that comprises: (a) a first layer of filter media that has first and second major surfaces and a perimeter and that contains active particulate that is bonded together; (b) a second layer of filter media that has first and second major surfaces and a perimeter and that contains active particulate that is bonded together; (c) a plenum that is disposed between the first and second layers of filter media such that the plenum interfaces with the second major surface of each layer of filter media; and (d) a housing sidewall that extends from the first layer of filter media to the second layer of filter media and that is secured to at least a portion of the perimeter of the first and second layers of filter media, wherein the first major surfaces of the first and second layers of filter media are each fluid permeable and are each in fluid communication with an exterior gas space, and wherein the first and second layers of filter media do not have a reduced thickness at the perimeter.