This set includes 2 durable, transparent plastic 15" discs, one with even divisions and one with odd. Each disc has concentric circles for ease when centering, and a number of radiating lines to accurately design patterns. The design includes evenly spaces holes throughout, so marks can be made on clay through the disk without removing it. Great for marking thrown pots before altering to precise shapes, making patterns for hand building, or simply evenly spacing designs or attachment. The MKM Decorating Disc makes creating an endless numbers of forms and designs quick, easy, and precise.