Contigo AUTOSEAL Stainless Steel Vacuum Insulated Tumbler, 16 Ounces, Black Patented AUTOSEAL lid is 100% leak-proof and 100% spill-proof Drinking made easy! Press to sip. Release to seal The AUTOSEAL Stainless Steel Mug automatically seals between sips to ensure no spills Vacuum-insulated technology keeps beverages hot for 4 hours, and cold for 12 hours Contoured body makes this travel mug easy to hold and easy on the eyes