Thermos vacuum insulation technology for maximum temperature retention, hot or cold. Durable stainless steel interior and exterior. Eastman Tritan copolyester inner liner is microwave and dishwasher safe. Wide mouth is easy to fill, eat from and clean. Cool to the touch with hot liquids, sweat-proof with cold. Utility patent and registered design patent pending. Dishwasher durable, top rack recommended. Keeps hot for 4 hours. Keeps cold for 9 hours. 12 oz