Heat and reheat foods with the convenience of a built-in steam vent using the Lock and Lock purely better 17 oz. vented glass food storage container. Featuring a patented 4-hinge locking system for freshness that lasts longer, Lock and Lock Purely better storage containers are constructed from borosilicate glass, which can withstand both high heat and sudden cooling but are 10% lighter than tempered glass for easy, on-the-go use. The airtight and leakproof lid has been durability tested to last up to 3 million uses and features an innovative steam vent to prevent pressure build-up when foods are heating or reheating. Plus, Lock and Lock purely better glass containers are microwave, freezer, oven and dishwasher safe. Lock and Lock purely better containers are also stain and odor resistant, easy to clean and come with a lifetime limited warranty for healthy, happy, no-worries food storage.Lock in airtight and leakproof performance with freshness that lasts with the Lock and Lock purely better 17 oz. vented food storage container.