a multiple cell flat molded from lightweight plastic . the cells are defined primarily by sinuous partition walls that are arranged to define an individual cell shape in the form of two opposed ogee arches connected at the wide ends of the arches . short lateral support ears are located in the cells and support the eggs with the egg surfaces spaced from the cell walls . the flats can be stacked or nested , and have special shapes at the ends for identification and end to end nesting when the stacks are used in the incubator .