The filter set is specifically designed with a size of just 0.3µm, making it small enough to capture the smallest particles, while also providing a longer lifespan for your air purifier. The Coway Airmega Air Purifier Filter set is a 3-stage filtration system that is specifically designed to remove 99.97% of airborne allergens, odours, and gases. It includes a True HEPA filter to capture ultrafine particles such as viruses, bacteria, fungi and pollen with an antimicrobial treatment for maximum air purification, as well as two carbon pre-filters to remove odours and gases from the air. The filter set is only 0.3µm in size and provides a longer lifespan for your air purifier. This powerful purifier is perfect for any home or office environment.