The pura universal lid functions on all pura bottles. It provides a totally watertight lid to any of our bottles. If you want to put hot liquids in any of our insulated bottles, the universal lid is the best choice. Use with our 5oz or 11oz to securely store breast milk, baby food, or a number of snacks as it is the perfect size for lunch boxes. The universal lid is dishwasher safe, shatterproof, and crafted from safe, anti-bacterial, 304 stainless steel and medical grade silicone.