Refrigerator filter. 27 cm x 26 cm. This is a new, unused item, but there may be some discoloration due to long-term storage. Please be aware of this. Can be used with a separately sold filter. https://jp.mercari.com/item/m58213859246?utm_source=android&utm_medium=share&utm_campaign=share-2&source_location=share This size is 31 cm x 25 cm. If you don't use a filter, it puts a strain on the refrigerator, reducing its function and shortening its lifespan.