Our Kaffe coffee mugs have a classic and timeless design with the benefit of high-tech tempered glass. Our double-wall glass construction is functional with superior heat retention, but with its clean and modern lines it is also truly elegant and a beautiful surprise for guests. Bring elegant and modern elegance to your home in the best combination of form and function. Coffee lovers, or anyone serious about handmade coffee, will love this set of European-inspired espresso cups. Superior materials mean long-lasting performance: Borosilicate glass is tempered for added strength, making it crack and shock-resistant.