The coffee mug made of food grade 18/8 stainless steel(304), with double vacuum insulation function, can effectively keep the temperature of the drink up to 8 hours, it keep drink hot in winter and keep drink cold in summer. Comparing with the glass cup and ceramic cup, this stainless steel coffee mug is more durable, easlier to clear, not easy to break. This smart thermos cup can also keep ice water, milk cup, keep warm for up to eight hours. Welcome to support customized logo.