Honeywell HPA300 comes with two different filtration systems, including a Pre-Carbon filter and a True HEPA filter. The carbon filter is known for its work against allergens, odor, and pollen and even kills minute microns that are present in the air. Additionally, the True HEPA filter is one of the best, with 99.97% efficiency that kills even 0.3 ounces of microns present in the air and offers absolute performance efficiency.