Bamboo Double Wall Insulation Cup-10oz. Because it`s real bamboo, no two are exactly alike, and every one you buy is unique! High quality stainless steel interior-the interior of all our flasks is made of food grade stainless steel. Strong resistance to odors, stains and bacteria. Use the latest vacuum insulation technology to keep pipes for coffee, tea and all other beverages warm for 12 hours, or chill them all day. Non-toxic – no harmful plastics, chemical odors or toxins. Increase your brand’s visibility with a product that is both functional and eye-catching.