This double-wall 16 oz. Cool Gear Mason Jar Tumbler takes tumblers and "mason jars" to the next level. The BPA free tumbler features a polypropylene straw with molded gasket, so the straw will not fall out when lid is screwed on. This unique mason jar tumbler makes a great Prom favor, graduation gift, or school fundraiser. Top shelf dishwasher safe and freezer safe.