Made with 18/8 food grade stainless steel, this 20oz tumbler features double-wall vacuum technology that can keep your drinks warm for up to 9 hours and cold for up to 12 hours. The skinny straight design makes it easy to carry around, and the sliding lid ensures your drinks won't spill. The rubber base provides extra grip to prevent slipping, and each set comes with two straws and a straw brush for easy cleaning.