The 12-inch and 8-inch ceramic trays include a lipped edge to contain sponges, a brush holder, a soap dispenser, or whatever you might store on it and prevents water runoff. There is a rectangular indentation for the Klaywell sponge stand and two circular indentations (12-inch tray) or one circular indentation (8-inch tray) for items such as a brush holder and/or soap dispenser. The tray is the base element in a modular design that allows you to customize your cleaning experience to the way YOU like to get things done.