Copper Moscow Mule Mug- 18oz. 18oz Copper Mug W/ Logo This replica is 100% copper and is available with or without a Moscow Mule graphic embossed. It holds 18 ounces. Built for those that want to experience authenticity, expand their collection, or add decorative accents to their bar. No machine washing. Must hand dry immediately to avoid spotting or patina. Note, there are also several different natural remedies for keeping your copper mugs looking their best and tarnish free by caring for them properly.