7-Stage Pre-Filter Stage 1 - Poly Propylene Mesh: Large particle collector of dust, hair and lint
Stage 2 - Anti-Microbial: Inhibits bacterial growth in filter
Stage 3 - Zeolite Pellets: VOC/Gas Adsorbent.
Stage 4 - Carbon Pellets: VOC/Gas Adsorbent.
Stage 5 - Potassium Permanganate: VOC/Gas Oxidizer
Stage 6 - Anti-Microbial: Inhibits bacterial growth in filter
Stage 7 - Poly Propylene Mesh: Large particle collector of dust, hair and lint

The Pre-Filter needs to be replaced every six months to a year depending on their environment