Beautifully designed Melitta® Double-Walled Coffee Glasses are made from the highest quality, double-walled, borosilicate glass. Keep your coffee insulated for a longer period of time, yet cool on the outside for safe handling. Dishwasher safe. Double-walled design to maintain temperature perfectly, the coffee should be hot, not your fingers. That's why these glasses are double-walled. You can hold the glass from the outside without any problems and at the same time your coffee stays nice and hot. Lightweight and heat resistant, made of high-quality borosilicate glass