Make everything about your food storage purely better with the Lock n Lock Purely Better 21 Oz Glass Rectangular Food Storage Container Set. Featuring a patented 4 hinge locking system for freshness that lasts longer, Lock n Lock Purely Better storage containers are constructed from borosilicate glass, which can withstand both high heat and sudden cooling but is 10 percent lighter than tempered glass for easy, on the go use. The airtight and leak-proof lid has been durability tested to last up to 3 million uses, and Lock n Lock Purely Better glass containers are microwave, freezer, oven, and dishwasher safe. Always Bpa Free, Lock n Lock Purely Better containers are 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 leak-proof performance with freshness that lasts with a set of four Lock n Lock Purely Better 21 Oz Food Storage Containers.