3 filters in 1 to achieve high performance from day one Original Philips filter that fits perfectly Our 3-layer filtration with NanoProtect HEPA, activated carbon and pre-filter ensures that you are protected against bacteria, pollen, dust, PM2.5, dander and gases from pets. Perfect fit for consistently high performance The original Philips filter is designed together with the unit itself to ensure a perfect fit, ensuring the unit continues to function smoothly.