This listing is for one medium sized hand-sculpted glass muller. These are used for grinding and mixing pigments with oil or other substances to make paints. Each muller is hand made so will be unique (not the specific one shown in the picture, but one very similar in size and shape). The mullers are approximately 3.5 to 4 inches tall, with a grinding/mixing surface between 1.7 and 2 inches across. The grinding/mixing surface has been ground flat to a fine grit, and not polished to provide a good fine mixing surface. I sculpt these from hot glass in my shop just south of Portland, Oregon. I am also happy to take requests for specific sizes and shapes.