4 Pack Copper Moscow Mule Mug - 18 ounce - With LOGO In the 1940s vodka became introduced to the mainstream by way of the Moscow Mule, traditionally served in copper mugs just like these. Smirnoff was the choice spirit for this popular drink, and by the 1950s vodka was the best selling liquor in America. This replica is 100% copper and is available with or without a Moscow Mule graphic engraved. It holds 18 ounces. Built for those that want to experience authenticity, expand their collection, or add decorative accents to their bar.