This piece is thrown on the potter's wheel from stoneware clay before ridges are added. These ridges mean the soap sits raised to prevent it from getting soggy, with water collecting in the circular troughs where it can be easily poured away. These dishes don't have a drainage hole meaning the water is contained and surfaces stay dry.
Please note that this is a handmade product and may differ slightly from the image shown. Flecks in the glaze and other irregularities are part of the character of the product and do not constitute flaws.