Sirius Double Wall Glass Tea Cup is gorgeous and well-designed! Sirius Double Wall Glass Tea Cup is a large 500ml size, ideal for any tea lover! Sirius is double walled, lightweight, yet sturdy and effortless to clean. Sirius’ double walled design makes sure that while your tea stays hot, the mug is cool to the touch. Our modern design keeps your drink at the ideal temperature much longer than a regular glass mug.