Featuring a 4-hinge locking system for freshness that lasts longer, LocknLock Purely Better storage containers are constructed from made-to-last Tritan(tm) that is 2X as hard as traditional plastic. The airtight and leakproof lid has been durability tested to last up to 3 million uses, and LocknLock Purely Better containers are microwave, freezer, and dishwasher safe. Always BPA-free, LocknLock Purely Better(tm) containers are stain and odor resistant, easy to clean, and come with a Lifetime Limited Warranty for healthy, happy, no-worries food storage.