CAMTOA Double Insulation Vacuum Stainless Steel Bottle Portable Cup Drink Hot or Cold Water Bottle for Travelling Mug Fishing Car Driving 350ML Double Wall Vacuum Insulation Technology - The air between the two walls is sucked out, in order to prevent outside temperature to affect the liquid inside the mug You can turn it upside down, shake it up, roll it, the liquid will not spill. Keeps HOT liquid HOT and COLD liquid COLD for Hours. Cap is designed to be easy to clean and dishwasher safe. Durable, impact-resistant construction and finger carry loop .