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. Stylish and practical espresso cup set: beautiful design with the benefit of the double glass wall to keep the cup cool to the touch. Keeps coffee warm: Double-walled glass isolates and keeps drinks hot longer. Comfortable and safe: hot drinks do not burn your hands and cold drinks do not form condensation. No burn marks or wet rings on the table.