These containers feature a 4-hinge locking system tested for up to 3 million uses. It is 100% airtight and leakproof, keeping food fresh and preventing spills. The set includes various container sizes, such as 1.8-cup square and 11-cup rectangular containers, all with lids. Price drops from $57.99 to $29. Shipping is free over $35 or free for Prime members.