Assuring Perfect Fitting: With our true HEPA filters, assure perfect fitting and compatibility with for HY4866 and YIOU M1 air purifiersHowever, ensuring the model before purchase is recommended. Innovative True HEPA Filtration: Adopts a unique honeycomb activated carbon structure improving purification effects and prolonging the service life. This improved design sustains optimal performance and efficiency of your air purifiers over extended periods. Economic and Enduring: Our pack includes 4 filters compatible with for HY4866 air purifiers exhibiting a lifespan of 8800 hours. For maintaining ultimate purification performance, replacing filters every six months is advised; although it depending on usage and environmental conditions. Quality Promise: While extending the durability of your air purifiers, we also prioritize the quality of our HEPA filters. Ensuring they are of high-quality, we them to comply with HEPA testing standards 's safety. Health and Well-being at the Forefront: a cleaner and healthier environment and your loved ones with our premium quality filters. With certified HEPA technology, our filters trap airborne particles ensuring a space for all. Colour:black+white Material:composite materials Package Contents: 4 x Air Purifier filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.