Factory-Reconditioned Hunter HR30713 HEPAtech 729 Air Purifier (2 pk) The HEPAtech filter will remove 99.97% of 0.1 micron particles from the air that passes through the filter The activated carbon pre-filter helps remove odors such as cooking, smoke and pet smells from the air; also traps lint, hair and other large particles to help extend the life and performance of the HEPAtech filter The ionizer improves the quality of air in the room by releasing negative ions into the air that attract positively charged dust, smoke and pollen particles This air purifier has been designed to operate quietly and efficiently; choose among three speeds to best meet your needs at different times Filter maintenance is critical to the performance of the air purifier; to help you determine when to change or clean the pre-filter and HEPAtech filter, the unit has built-in life counters that keep track of the life remaining of each filter