Solenco CF8500 Air Purifier 4-in-1 H13 Medical Antiviral FilterDescription Pre filter (removes the large airborne particles) Medical Grade HEPA (H13) filter captures up to 99,975% of particles that are 0. 1 microns in diameter. Activated Carbon filter (removes smells, odours and SO2 which is the main pollutant of Eskom) Antiviral Filter contains silver ions and copper ions are added to the material, and copper ions attack the proteins and amino acids of cells, so that silver ions invade cells and finally kill