These are special protective inserts for our 8-12" Purple Sunreed Carrying Bowl Cases. These bowl cases are hard bowl cases that are extra protective for crystal bowls. The extra inserts help protect bowls that are odd diameters such as 5-7", 9" and 11." These sizes of crystal bowls do not normally perfectly fit in these extra protective cases. These inserts add an extra layer of protection for these bowl sizes. If you have an 11" bowl you will want to choose the 12" size of insert, and if you have a 9" bowl you will want to choose the 10" size of insert, and if you have under a 8" bowl, including clear bowls, you will want to choose the 8" size insert.