Double walled glass mugs are not unique in our JoyJolt collections, but we wanted to give our costumers a subtly exciting twist to our classic design. The Caleo Collection features an assortment of double walled mugs for hot or cold drinks, made with only the best hand blown glass now with a new modern style. The design has an elegant angled curve to its base. It's sleek, it's unique, it's Caleo. Following our Caleo's telltale design, the tea mug in this series has a double wall application to maintain your dink's hot temperature while protecting your hands from the heat. The espresso cups are specifically sized to hold the perfect 2 oz. espresso shot. The set of two mugs are made of pristine hand blown glass that can withstand a temperature of up 350 degrees Fahrenheit; this heat can be from the microwave, the liquid itself, a dishwasher or even an oven! Similarly, our Caleo mugs are freezer safe, allowing hot coffee to be turned iced without having to change cups! By using only top quality borosilicate-glass for our mugs, we are able to give our customers durability, functionality and style all in one. Caleo mugs are must-have additions to your cabinets that, at JoyJolt, we know will significantly improve your coffee drinking experiences.Details:Clear2 oz. capacity4 glassesDishwasher, microwave, oven and freezer safeBorosilicate glass