these are the most purified containers we have ever made. as one of the world's leading food storage container makers, we continue our tradition of supplying the products with our airtight food containers. we take pride in providing the most durable and safe products for our valued customers. scientifically designed for vertical and horizontal stacking, it saves space, protects your food, and streamlines your cabinets, countertops, and more. lock & lock airtight containers keep food fresher longer. no more mess in your lunch box, refrigerator, or freezer they are all leak proof as well. lock & lock plastic containers are very convenient to go from refrigerator to tabletop with clean and attractive designs. the locking system provides equal pressure on all four sides of the hollow silicone seal ensuring air and water tightness. earth and family friendly these are all bpa free. feel safe and sound when using lock & lock for you and your family with our durable materials.