Thank you for viewing. This is an ozone removal filter for the Airdog air purifier. I originally intended to purchase the one for X3, but I accidentally bought the one for X5, so I am selling it unused. Also, since the price includes shipping, you can purchase it more affordably than ordering from the manufacturer's official website. This is recommended for those who are "at the replacement time but want to save a little money." [Compatible Models] ・Airdog X5s ・Airdog X5D ※Actual Size ・Width (W): Approximately 26.7cm ・Depth (D): Approximately 22.7cm (For X5 size) [Condition] ・Unused (due to incorrect size) ・Filter that must not be washed with water ・No noticeable stains or damage [About Packaging] As shown in the third photo, It comes with the cushioning material (foam) that arrived from the manufacturer. I will pack it securely in the same way when shipping. [Notes] ・Cannot be used for X3 / X3s / X3D ・Please be sure to check the compatible models before purchasing. ・Returns due to size differences are not accepted. Instant purchase is OK. If you have any questions, please feel free to comment.