The Stanley thermos is vacuum insulated and will keep drinks hot for 15 hours or cold for 60 hours. It is 18/8 stainless steel, will not rust and is naturally BPA-free. The insulated lid doubles as a cup and it is leak proof and fully packable. The smaller thermos is perfect to make hot drinks or soup for one to take to work, while the larger size is a great thermos to fill for picnics or sharing a hot toddy on a winter walk. With a monogrammed JimmieWilliam leather sleeve these make a perfect gift.