Navy, The Miles thermos flask has smart vacuum insulation that keeps water cold for up to 15 hours and hot drinks warm for up to 6 hours. The vacuum insulation means that it will never create condensation, so your bag is kept dry. The flask is made of 18/8 stainless steel, so it doesn’t absorb the taste or smell of any previous contents. The thermos flask is free of toxic substances, and can be used for a lifetime. Using it results in fewer plastic bottles that are thrown away, saving the ocean and the environment.