H13 true hepa filter: gcz hepa air purifier is equipped with a 4-stage filtration system including pre-filter, true h13 hepa filter, activated carbon filter, non-woven fabric filter, captures particles as small as 0.3 microns, can reduces up to 99.97% of germs, dust, pollen, pet dander, mold, smoke, hair, and odor. filter replacement reminder: our machines come with a 3000 hour filter change reminder. when the filter is used for 3000 hours, the indicator light will flash. depending on air conditions, we recommend you replace the filter every 6-8 months
