Dual-sided filters are comprised of a true HEPA filter with highly efficient activated carbon honeycomb granules and a durable mesh pre-filter. Z-7000. Captures 99.99% of airborne viruses and bacteria, breaks down volatile organic compounds (VOCs) and odours. Durable mesh pre-filter captures larger particles such as dust. The pre-filter can be hand washed in between filter replacements. 2 per package.