●Filter Compatible with: Filter B, AC4825 AC4300 AC4800 AC4900 AC4850 ●VALUE PACK:4 Filters B H13 True HEPA Filter & 6 Extra Replacement Carbon Pre Filter. You can simply change the filters more frequently. ●H13 True HEPA: HEPA filters are made of H13 grade ture HEPA filter media, which can help capture small particles as small as 0.3 microns. ●CARBON PREFILTER:Carbon pre-filters are made of high efficiency activated carbon and sponge, which can help capture large paritilia and absorb odors from smoke and cooking. ●Our Guarantee We attach great importance to our product quality and your satisfaction. If you have any questions, please feel free to contact our customer service.