Air purification filters are used for additional coarse purification of the supply air.

Class G3 filters retain up to 90% of particles larger than 10 microns: pollen and fluff, spores, soot, coal mine dust, metallurgical dust and coarse dust.

Class G2 filters retain up to 80% of particles larger than 10 microns: fine sand, coal dust, cement dust, fly ash, textile fibers, mold spores, wood dust.

G4+CARBON class filters retain particles > 5 microns: milk powder, oil aerosol, fog, fine dust, automobile emissions, tobacco smoke, lead dust.

The filters are reusable and require periodic cleaning (as they become dirty). The user can install, maintain, and replace the filters independently.