Filters bacteria and scale present in the water before they enter the air. The 30 mm thick cellulose fiber filter made up of 12 layers ensures efficient and consistent humidification performance for up to 6 months per filter 12-layer honeycomb structure to achieve optimal water absorption and evaporation efficiency. Compatible with Philips humidifiers HU4801 or 01, HU4803 or 01, HU4803 or 70, HU4811 or 10, HU4811 or 30, HU4811 or 60, HU4811 or 90, HU4813 or 10, HU4814 or 10 - Compatible with FY24 01 filter or 30 (replaces FY240) 1 or 10) Package contents: 5 humidifier filters Note: The data is all measured manually, please allow 1-3cm error due to differences in light and display, there may be color differences, please refer to actual item received.