WOW Containers configure to fit all of your food storage needs. Unique design allows each piece to function as a lid or a base. Stop hunting through your cabinets and drawers for matching containers and lids. Forty-piece, stackable system includes four sizes (2, 4, 8, and 12 cups). Create over 100 configurations for the perfect container, every time. Fresh-lock tabs ensure a tight seal. Freezer, microwave and dishwasher-safe. Plastic.