4 Pack 100% pure copper Kyiv Mule mugs. Copper mugs are a great conversation starter and are considered an essential part of the traditional Kyiv Mule drink. Each mug features a beautiful hammered design and holds 18 ounces. The metal insulates the temperature of chilled ginger beer to keep your drink cold and refreshing. The cups are also great for iced tea, iced coffee, rum, tequila, whiskey, gin, or beer. Mugs measure 3.7" wide (5.25" including handle) and 3.8" tall Note: Copper drinkware should not be used with acidic substances like vinegar, fruit juice, or wine