Dutis Microwave Container Set 4 Piece Microwave and dishwasher safe food storage containers will not melt and will not harm your food or your safety. BPA FREE all pieces of the containers are made of BPA free plastic. Locking Lids make a strong airtight and watertight seal preventing food spoilage. All storage containers are freezer safe, food will not spoil and containers will not crack. Storage saver units can be stackable and will not clutter your kitchen.