[Precision Compatibility & 360° Design] Specifically engineered A230 filter replacement Size O (1712-0100-00) for seamless compatibility with Winix A230 and A231 air purifiers. The 360° all-in-one 4-stage configuration supports even airflow distribution, helping your purifier maintain strong, stable performance in bedrooms, living rooms and offices [3-Stage Filtration System] This A231 filter replacement combines a fine mesh pre-filter, H13 true HEPA filter and high-efficiency activated carbon layer. The pre-filter traps hair, lint and large particles, while the HEPA core captures fine dust and allergens. [H13 True HEPA Filtration] The A231 air purifier replacement filter Size O is built with H13 true HEPA media that captures up to 99% of airborne particles as small as 0.3 microns, including dust, pollen, pet dander . This advanced filtration helps relieve indoor air concerns, supporting more comfortable breathing for families [Cost-Effective Long-Lasting Value] Each A231 replacement filter pack includes 2 high-quality value filters (1712-0110-00), giving you up to 12 months of effective purification coverage per set under normal use. This economical option reduces the frequency of purchases, [Quick Tool-Free Installation & Service] The A230 filter is designed for fast, hassle-free replacement with no tools or technical skills required-simply open the purifier, remove the old filter and insert the cartridge. If you encounter any issues or questions, Color: As Shown Material: plastic Package Contents: 2* Air Purifier Filter