6 inch activated virgin charcoal carbon filter. 6" flange fits 6" duct fans and ducting. 400 CFM air flow rating. 14 inches tall. Comes with a white pre-filter for removing larger air particulates that can be machine or hand washed every few months to extend the life of the filter. This carbon filter lasts approximately 1.5 years with daily use. Purify your air and remove odors at the same time. Reduces mold, pollen and other air particulates by 99.5%.