BarWerks Moscow Mule 100% Copper Mugs 16oz (Set of 4) No Plating, Stainless Steel or Nickel Lining. Set of four (4) high quality Moscow Mule mugs. These mugs are constructed of 100% pure Copper. No plating, stainless steel or nickel linings. Oversized handles are welded to the mug. No rivets to violate the integrity of the vessel. Welds are clean and high quality. Only the best best mugs pass our quality assurance. Solid copper is great for light beer, iced tea and coffee, whiskey, rum, and other mixed drinks. BarWerks quality for a lifetime of use. We guarantee our mugs! The all copper construction makes for a quick frosting mug. Leave them in your freezer case. Hand wash only.