Perfect Compatibility: AP0601 Air Purifier Replacement Filter for AIRTO is perfectly compatible with AP0601 Air Purifier. 4-IN-1 Filter Stage: Our AP0601 replacement filters for AIRTO is designed in 4-in-1 True HEPA Filtration, including Pre-Filter layer, Blue nylon layer, H13 Grade True HEPA Filter, and high efficiency activated carbon filter H13 True HEPA Filter: The AP0601-RF filter replacement captures 99.97% of particles down to 0.3 Micrometres in size, creating air and your family to breath and sleep easier High-efficiency AP0601 Filter: 2 Pack for airto AP0601 Replacement Filter, To keep it running at high performance, it is recommended to replace the Core AP0601-RF filter every 6-8 months Colour:Blue Material:composite material Package Contents: 2 * air filter replacement 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.