Product DescriptionProduct Name: Suitable for Philips Air Purifier AC3822 AC3824 Humidification Filter FY3435 Filter Impurity BacteriaOuter diameter 245mmInner circle aperture 25mmThickness 19mmColor: BlueFunctionReplace the old one and nstall new one , change it every three months. Philips new humidifier filter - a small yet effective device, that can bring clean air to your home in a compact and simplicity way.One button effortless controlIntelligent auto purification modeColor indication for real-time air qualityCompact but efficient purificationEfficient purificationEffective purification nano-sized particlesCompact sizeQuiet as whisperUltra-quiet operation with dimmed light in sleep modeSuitable for Philips AC3822 AC3824