The 16x25x4 MERV 11 Pleated AC Furnace Air Filters are designed for optimal filtration and indoor air quality. With a MERV rating of 8 and electrostatic filtration technology, these filters capture airborne particles to keep your home healthy. The filters are made with a moisture-resistant and antimicrobial material, making them ideal for use in both air conditioners and furnaces. This 4 pack of Purolator filters lasts for 3 months and provides efficient and effective filtration for your heating and cooling systems. New in box see pictures for description. D13