Captures 99.97% of all particles The NanoProtect HEPA Series 3 filter captures 99.97% of 0.3 μm particles, including common allergens, dust, dirt, bacteria and some viruses. 12 months lifetime for long-lasting performance. Long-lasting performance - As long as 24 months lifetime Excellent cleaning - Captures 99.97% of all particles Long lifetime The Philips NanoProtect HEPA Series 3 filter has 111 optimized pleats. This corresponds to an unfolded area of approximately 1.6 m² to ensure a long life of up to 24 months. Superior performance The Philips NanoProtect HEPA Series 3 filter is made of high quality material. It captures up to 99.97%* of all particles as small as 0.3 μm - the size of the most common airborne allergens, harmful particles, bacteria* and viruses*. The high quality filter with a solid and stable structure ensures that ll air passes through the filter and delivers high filtration performance.