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 grey transparent plastic sliding lid with a rubber gasket, which is well tightness. It is easily swiped to open while keeping away from splashing. Closing the sliding lid keeps clean when do not use the mug. There is drinking hole on the top. The coffee mug is made of food-grade 304 stainless steel, liner of coffee mug will not produce any taste and will not rust. The structure of the coffee mug body is sturdy, could be used for a long period of time. 17oz mug is lightweight and easy to carry. The prices are based on sea shipping for quantity over 1,000 pieces.