This set of 10-piece 30mm ceramic ring sizing pellets will help you achieve the perfectly sized and shaped rings every time. These ceramic ring sizers do not shrink or burn during sintering. As the PMC or metal clay sinters, it shrinks around the pellet, making the ring forms to the exact diameter of the pellet. Why risk incorrect shrinkage with your PMC rings when sintering and why spend money on disposable pellets when this set of 20mm pellets can be used again and again. Quality made in Japan.Longer than the 20mm pellets, these 30mm pellets are great for broader rings, bands and jewelry, especially those that will hold larger gems and stones. Also, these ring sizers are made from quality materials, and are reusable.Simply wrap the pellet in a ceramic tape. To hold it in place, an adhesive tape like scotch tape can be used before placing it inside the metal clay ring. After that, you can fire it in a kiln. Once you are done with the sintering, allow finished PMC jewelry to cool and then, remove the pellet for later use.The Japanese sizes are the ones written in the ceramic ring pellets, please see the table below for the approximate equivalent sizes. United States, Canada United Kingdom, Ireland, Australia, New Zealand India, China, Japan, South America Italy,• 4½, I, 8, 8• 5, J½, 9, 9.25• 5½, K½, 10, 10.5• 6, L½, 11, 11.75• 6¼, M, 12, 12.5• 6½, M½, 13, 13.25• 7, N½, 14, 14.5• 7½, O½, 15, 15.75• 8, P½, 16, 17• 8½, Q½, 17, 18.25No English instruction available.