The double-walled construction of these teacups allows one to hold the cup comfortably between the fingers even when the cup contains freshly brewed hot tea. Made of clear heat-resistant glass. Please note that these cups hold about 1.6 ounces and are designed for imbibing tea in the manner of the Chinese Gong-Fu-style tea ceremony. This style of tea drinking allows the smaller volume of tea in the cup to cool to a drinkable temperature more quickly than a greater amount of tea in larger mugs. These cups would be about the size of the tea cups found at your local Chinese restaurant. These smaller cups are also perfect for expresso coffee. The set of six cups comes with complimentary Bana Pu-erh tea samples. (Important note: Double-walled tea cups are often manufactured with a very small annular opening near the bottom of the cup to allow for release of air-pressure. Prolonged immersion of these cups in water may result in moisture entering within the double walls.) Bana Tea products ship from the United States.