Made for inside big storage containers. It takes two sifting inserts for each big storage tote which approximately measures 32 inch long by 16 inches wide. Sifting inserts are placed inside on bottom. There is 4 - sifting inserts to a shipping box. (Please note that the kettle popper doesn't come with the big plastic storage totes) They are used with kettle corn poppers to speed up batches and easier of sorting when you have extra employees. Also works great for big batches and mixing popcorn like carmel apple and other great gourmet popcorn flavors.