AXP 400 Filter (2 Pack)The Air X Pro uses a specialist 5 layer filter cartridge, these layers are listed below: H13 HEPA The Medical Grade H13 HEPA filters out 99. 95% of all particles down to 0. 1 microns. Activated Carbon with High Iodine Content The Carbon filter will remove harmful gases and Volatile Organic Compounds (VOC) usually released by household products. Formaldehyde Catalyst Will remove bad odours and smells from the air. Cold Contact Filter Also known as a