The Koziol Wine Glasses Super Glass - 200 ml - 2 Pieces is really a perfect wine glass for outdoor use. The wine glasses are made of the durable Superglass, which makes them unbreakable and environmentally friendly. The glasses insulate up to 4x better than regular glass, making them perfect for keeping your wine well chilled and experiencing the best flavor. After use, the glasses can of course go in the dishwasher.