Rev up with a fulfilling cup of coffee in these Double Double Friendship Heart Amour Coffee Mugs or serve with love to your friends and family. Made with a double layer of mouth-blown borosilicate glass, each glass will keep hot and cold drinks insulated while the outside surface will remain comfortable in your hands. Two layers of this glass are used to give it ample insulation, style, and to create an optical illusion. The double wall creates an effect where the drink appears as though it is 'floating' within the glass. When filled with your favorite beverage, the unique design of this heart coffee mug will be 'lovely' to the eye. Surprise your colleague, a relative, or a friend with this double layer heart cup on their birthday, anniversary, or any other special occasion.