Enjoy your favorite drink like never before with the JoyJolt Spike Double-wall Glass Cups! These 2-capacity double wall glasses are perfectly suited for a multitude of hot and cold beverages as well as desserts. Individually handmade of heat-resistant borosilicate glasses they are designed to keep your liquids hot or cold for a longer period while keeping your hands cool to the touch it also eliminates the need for coasters as no messy condensation will occur. JoyJolt double wall glasses are mouth-blown by expert artisans using borosilicate glass. Borosilicate is stronger than traditional soda-lime glass and can be used for everything from drinkware to cookware. Due to the natural properties of the boron particles the glass is held together tighter resulting in a stronger lighter glass. Borosilicate glass doesn t need to be as thick as traditional glass to be just as strong due to the bonding capability of boron oxide.