If you suffer from a stuffy nose, sneezing, and headaches around your home the problem might be as simple as poor indoor air quality, with the Filtrete 4" Allergen Reduction Deep Pleat Air Filter - 4-Pack replacement air filter being the antidote. The 4-inch deep pleated air filter has a greater depth that translates to a larger surface area. In conjunction with the already excellent Filtrete 3-in-1 filter technology that traps dirt and allows for greater air flow to deliver a much greater reduction to airborne contaminants. Everything from cooking to pollen that comes in from outside can cause respiratory discomfort. With your air conditioning system being at the heart of your home's air flow, an air filter has a wonderful potential to reduce discomfort and making breathing easier.