A new Era of straw tumbler is here. Our Era tumbler is totally leakproof, andmade for stress free sips on the go. It has our fully leakproof. Turn lid that works for both cold and carbonated beverages, ColdKey metal straw for minimizing the amount of plastic sitting in your water, BevGuard technology to keep ice for 24+ hours, and a cup-holder friendly base so you can enjoy 40ozof your favorite beverage, free of leaks and spills throughout your daily journey.Era Tumblers are 100% leakproof withcold beverages and carbonated beverageswith ice when in the locked position. Not recommended to be used in the locked position withhot beverages.