12 oz/17 oz mug is lightweight and easy to carry, the surface of it is matte powder coating, and this sweat-free design makes the coffee mug easy to grip, and gently fits into your hand. The coffee mug is vacuum double insulated. The double-walled insulation design ensures beverage can stay either hot or cold over time. Let you enjoy hot or cold drinks. The plastic lid with a rubber gasket is well-tight. It is easy to open while keeping away from splashing. Closing the lid keeps clean when do not use the mug. The coffee mug is made of food-grade 18/8 stainless steel, the liner of the coffee mug will not produce any taste and will not rust, hand wash is recommended. The structure of the coffee mug body is sturdy, could be used for a long period.