BarWerks Moscow Mule 100% Copper Mugs 16oz No plating, stainless steel or nickel lining. Constructed of 100% pure Copper. No plating, stainless steel or nickel linings. Oversize handle is welded to the mug. No rivets to violate the integrity of the vessel. Welds are clean and high quality. Only the best mugs pass our quality assurance team. Solid copper is great for light beer, iced tea and coffee, whiskey, rum, and other mixed drinks. BarWare 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 Recommended.