An 18” pizza could easily fit into the storage container, not really. The separators are just too small to be effective at all for the average sized pizza slice.
Dividers can be used as a plate to reheat pizza in the microwave. Can be washed in the dishwasher and can be microwaved. I usually throw the leftover pizza in a ziplock bag and it ends up all smushed and the toppings get all over the place.
Not as good as advertised. I love the collapsible container but the dividers tore the toppings off every single slice. The lid is useless you cannot snap the top to the bottom.