【Compatible with】--Compatible with ECOSELF HAP604 Purifier, please ensure that the model matches. 【3-in-1 Filtertion System】--Including a fine primary filter, H13 true HP filter and high efficiency activated carbon filter. 【Activated Carbon Filter】--Highly effective activated carbon can help reduce indoor odors from smoke, cooking and pet odors. 【Life Time】--We recommend replacing the filter every 3-4 months, depending on usage. 【Buy With Confidence】--If you have any questions, you can contact us at any time and we will guarantee to provide services to your satisfaction. hap604