Ideal for keeping your beverages cold or hot when you're on the go or just lounging at home. The Hippo Mug is built to hold 40 ounces of your favorite cold and hot beverages, keeping them cold for up to 11 hours and hot for up to 7 hours with its copper lined, double wall stainless steel construction. Each mug is strong and durable, from its handle to a convenient screw-on clear straw lid with a twist closure, giving you the option of drinking with or without the removable straw.