Thermos Stainless Steel, Vacuum Insulated, 16-ounce Travel Mug Combo Set Thermos double-wall vacuum insulation locks in temperature to preserve flavor and freshness Thermos double wall vacuum insulation for maximum temperature retention, hot or cold Unbreakable stainless steel interior and exterior Cool to the touch with hot liquids, sweat-proof with cold Leak-proof lid with one hand push button operation