Supplied as a set of two by Bodum, these medium highball glasses have been individually mouth-blown by expert artisans, Bodum\'s proprietary Double Wall Glasses feature two walls of borosilicate glass with air in between, creating a highly effective layer of insulation. The silicone valve at the base allows for changes in pressure and are also perfect for serving ice cream and other desserts as they keep ice solid for longer. Dishwasher safe for ease of cleaning, these glasses are also microwave and oven safe up to 180 degrees.