tea gift double walled glass cup 350 ml / 12 oz with 2 flowering green tea balls blooming. great clear double wall insulated mug for serving coffee, tea, hot chocolate, latte, espresso. eco nava tea gift double walled glass cup 350ml / 12 oz with 2 flowering green tea balls blooming. borosilicate glass is light in weight than normal glass mugs and keeps hot drinks longer.