Old Dominion 100% Copper Moscow Mule Mug, Set of 4 (Smooth Small Handle) Accept no substitutes! The original Moscow Mule Mug by Old Dominion is 100% SOLID COPPER. All Old Dominion products are 100% FDA Approved. Guaranteed to be free of Manufacturing Defects, simply return the items through the Amazon return process for free replacements. Each mug is coated with tarnish resistant lacquer to preserve its beauty and luster. Many styles available to make your bar ware collect stand out in a unique way!