Shape 0 is the smallest rib. The traditional kidney-shape is the most universally recognized clay tool. These little ribs can get into tight places and are good for detail work. The Red Very Soft is excellent for finishing rims.
Whether you are throwing clay on the wheel, hand building or sculpting, the pottery rib is a classic and essential tool. It acts as an extension of the potters hand to create shapes and surfaces that fingers alone can not achieve.