Plenty of factors will shorten a carbon filter's lifespan, with heavy usage having the greatest impact. The harder the charcoal bedding works to scrub out odors the faster it will need to be replaced. This pre-filter cloth adds a layer of protection by blocking out debris like dust, lint, and additional particles that can negatively impact your filter's effectiveness. Built to be machine-washable, these cloths will protect carbon filters for up to six months!