The High Efficiency Carbon Filter uses Air Reborn Odor Removal Formula and customized high-grade granular activated carbon to effectively remove vehicle exhaust and toxin gas from air pollution and wildfire. This filter is exclusively designed for the Levoit Core 300 and Core 300S air purifiers to maintain peak performance. With a cost-effective price, it saves much cost for your all-year-round air cleaning needs. It is recommended to replace filters every 6-8 months. The True HEPA Filter meets the High-Efficiency Particulate Air (HEPA) standard, filtering fine airborne particles such as pet dander, dust mites, and pollen, effectively helping improve allergies. The ultra-fine Nylon Pre-Filter captures large particles like dust, lint, fibers, hair, and pet fur, also helping to maximize the filter's life. Filters are sealed to protect their service time. Remove the plastic packaging of new filters before running the air purifier. Please feel free to contact Levoit Customer Service Team for any support needed.