Vacuum Insulated Thermal Water Bottles for Hot or Cold Drinks are made of food-grade 18/8 (304) stainless steel. It is easier not to spill our when the mouth is narrower versus the wide mouth kind. This design keeps your drinks as cold (or hot) as science allows. With stainless steel construction, double-wall vacuum insulation. Perfect Size: Comfortably carry our slim sports water bottle in your hand. Unlike traditional camp mugs, this double-wall vacuum-insulated body protects hands from hot or cold contents while keeping coffee, chili, oatmeal – you name it – well-insulated. What you like, what we do!