4 H Solid Copper Moscow Mule Mug with Flat Handle 16 oz - Set of 4Vodka, fresh lime juice, and ginger beer combined in a gleaming, solid copper mug are the key ingredients to making the original Moscow Mule cocktailintroduced to the U. S. in 1941. In addition to the signature Moscow Mule, these classic mugs may also be filled with cold beer or other cooling libations. Solid copper construction. High polished finish. Unlined, unlacquered solid copper (will age to a natural patina unless polished).