Extra Large Naniwa Flattening Stone 12" x 6"The Extra Large Naniwa Flattening Stone is designed for serious water stone maintenance. Measuring 300mm by 150mm and 20mm thick, its generous size and 220 grit surface provide efficient, even flattening for large stones. Equipped with solid rubber feet, it stays firmly in place during use, allowing you to concentrate fully on your sharpening work. This stone requires soaking before use to ensure optimal performance and smooth, consistent results.