1. Perfectly compatible with AC4825, AC4825E, AC4300, AC4800, AC4900, AC4850, AP2200CA, Please note that this is not an original manufacturer product, but is specifically designed to be compatible with the models listed. 2. Enjoy fresh, clean air all year round with the FLT4825 replacement filter. This H13 True HEPA filter combined with a high-efficiency activated carbon filter can effectively filter airborne particles as small as 0.3 microns, and can also decompose unpleasant household odors and wildfire gases, keeping your living environment fresh and comfortable. Designed to relieve the uncomfortable symptoms caused by problematic air, this filter is a must-have for anyone who wants to improve indoor air quality. 3. Package contains 2 H13 True HEPA filters and 6 activated carbon filters. Maintaining optimal air quality in your home or office is essential to your health and wellness. Therefore, it is crucial to replace the filters of your air purifier regularly. For optimal performance, we recommend replacing the HEPA filter every 6-8 months and the pre-filter every 2-3 months. 4. Replacing the filter in the machine is very simple and does not require any tools. Simply remove the old filter and insert the new filter into the machine. Once installed, turn on the machine and press and hold the UV button for 5 seconds until the flashing red light turns off, indicating that the filter has been successfully reset.