The double wall vacuum insulated tumbler can keep drinks stay hot up to 6 hours and cold up to 24 hours.Our tumbler is made from high quality premium 304 18/8 food grade stainless steel, BPA Free.The lid with ring gasket tightly covers the 30 oz stainless steel tumbler that prevents water from overflowing. The bottom of the travel mug is conveniently sized to fit car cup holders for easy portability. Fill with coffee, sweet tea, ice water, milkshakes, lemonade and more.