Insulates and retains steam to maintain the temperature of both hot and cold cocktails/beverages. Covers the surface of the glass and creates an airtight seal to prevent unwanted insects and debris from falling into your drinks. Seals tight on all smooth rim surfaces including stainless steel, glass, plastic and melamine. Prevents spills by creating an airtight, watertight seal for reheating and storing. Saves on plastic wrap because you can use it again and again. Made of food grade silicone. Oven safe, microwave safe and dishwasher safe. Lilypad.