Made of durable, heat and condensation-resistant, mouth-blown borosilicate glass of the finest quality, the 12 oz Serafino glasses are among the most popular glasses in the Ozeri Artisan Series of award-winning handcrafted drinkware. Each glass features an elegant double-walled design that suspends beverages within an inner wall for the ultimate insulation, preserving drinks at their ideal temperature. The Serafino's unique double-wall design creates an engaging optical effect, while the wraparound contour provides a natural aesthetic grip. Each glass is made to keep your hands cool even with your hottest drinks, and free of condensation with your chilled beverages. The patented Serafino glasses are great for coffee, cappuccinos, hot or iced teas, cocktails, frozen beverages and much more. Whether it is an occasion for a glass of wine, coffee, or some other beverage, borosilicate glass is completely resistant to acids, and your Ozeri glasses will never lose their original sheen. Each set contains 2 handmade glasses designed for lifetime use. The Serafino glasses are completely microwave and freezer safe..