Shinkodo Pure Copper Hammered Tumblers - Set of 2 These are high-quality tumblers made in Japan. They are perfect for cold drinks such as beer, cold sake, and iced coffee. I received these from an acquaintance and have kept them stored at home without using them. Size: 250ml Features of Copper Copper products have a unique, beautiful color and shine, and you'll grow to love them more the longer you use them. The cups you have received are made of copper, which has good thermal conductivity. When you pour beer into them, you'll feel the coldness, which is why beer connoisseurs say that drinking beer from a copper mug is the best! Also, not only for beer but also for iced coffee and other cold drinks, they are very popular. In addition, copper has a strong antibacterial effect called oligodynamic action (copper ion action), and it has been said for a long time that "water in a copper pot does not rot." For this reason, unlike materials such as pottery and glass, copper vases do not cause the water to rot, so flowers last longer and their colors remain vivid. Please understand that these have been stored at home.