Horn is one of those materials that was used a lot in the 18th and 19th century and now you hardly ever see it. These tumblers are made of cow horn and therefore they are sturdy and light. Each one is a little bit different and they vary quite a bit in size. The sides and the bottom are formed from horn and they are lined with a food safe modern sealant to keep them from leaking. Probably not the best container for hot liquids. Imported.