This insulated drink mug is made of quality materials, is sturdy and easily operated with one hand. I'm especially impressed by the snug fit of both the stopper and lid gasket. I also appreciate the flip lock on the side as it prevents accidental opening and spillage. The adjustable carry handle is also a welcome bonus. So far, it's kept my drinks cold for six hours but I suspect it would go much longer given the opportunity. Definately a plus in my book!