The dual-action Carbon/Gas Trap/VOC filters last for 6 months under normal use and reduces toxic ozone, gas, odors and VOCs volatile organic compounds. Our AIR Doctor Universal Genuine dual-action Carbon/Gas Trap/VOC filters for AirDoctor AD5000 and AD55000 last for 6 months under normal use. They capture toxic ozone, gas, odors and VOCs volatile organic compounds. These filters fit both the AirDoctor AD5000 and AD55000 units. It is part of a powerful air purification system that captures particles at 0.003 microns, which is 100 times smaller than the HEPA standard thus much more powerful than most other premium HEPA filters! The AirDoctor provides professional UltraHEPA filtration whether you are looking for home air purifiers that are superb for offices classrooms hospitals, etc. Before replacing the UltraHEPA or carbon/gas trap/VOC filter of your AirDoctor air purifier, turn off and unplug the unit from the electrical outlet and read all safety instructions and important warnings in this owner’s manual. Customers who purchased this item also purchased: AirDoctor 3500, AD3500, AD 3500, AirDoctor AD 3500, AirDoctor 5500, AirDoctor AD 5500, AirDoctor 2000, AirDoctor AD2000, AirDoctor 1000