The Koziol Wine Glasses Superglass - 300 ml - 2 Pieces is truly 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 4 times better than regular glass, making them perfect for keeping your wine cool and experiencing the taste optimally. After use, the glasses can of course be placed in the dishwasher.