Add some extra storage to your Kallax shelving unit with this IKEA Kallax Insert. The solid white fiberboard insert comes with four shelves, measuring 13x13 inches each, providing ample space for books, decor, or even your collection of vinyl records. Assembly is required, but it's a quick and easy process, making it perfect for those who want to add some extra functionality to their Kallax unit without any hassle. This insert is suitable for the Kallax shelving unit and is model number 404.237.19.