These replacement PreSorb and HEPA filters are specifically for use with the Vornado AQS25 and AQS35 portable room air cleaners. The PreSorb activated carbon pre-filter reduces odors and traps many airborne volatile organic compounds (VOCs). The HEPA filter captures bacteria and viruses. The PreSorb filter should be replaced every 3-4 months while the HEPA filter should be replaced every few years - depending upon usage and operating environment.
