Beer steins were invented in Germany as traditional drinking mugs. German beer steins are often capped with a hinged lid which can be flipped open with the thumb. These "lidded beer steins" served a purpose, to keep flies out of one's beverage. "Stein" is the German word for stone since early beer steins were made of stoneware. Beer steins can also be made of wood, porcelain, pewter, silver or glass.
For more German beer steins check out the following: