The Half Moon Ceramic Baking Stone for the Large EGGspander System turns your EGG into a fire brick oven, great for making breads, desserts and other baked items. The beauty of the Half Moon Ceramic Baking Stone is that you can cook indirect on one half of the cooking grid, while keeping the other half of the grid available for roasting meats or vegetables. Purchasing two Half Moon Ceramic Baking Stones transform the EGGspander System into a convection oven, just like the convEGGtor!