The 'Convention Cocktail Tumbler' from Schott Zwiesel is a small crystal glass tumbler designed for short drinks and spirits. The Convention series of crystal glass tumblers from Schott Zwiesel have in common a thick, heavy base - rounded at the sides - that leads into a perfectly cylindrical body. Included in this range are glass tumblers for beers and juices, 'old-fashioned' whisky glasses and shot glasses for your best Tequila. Machine-blown using patented Tritan crystal technology. Dishwasher safe.