Era Flip 30 oz. is the world's first 100% leakproof, covered, flip-down, straw tumbler. It has our fully leakproof SlideSeal(TM) lid that works for both cold and iced carbonated beverages, SoftSip(TM) silicone straw so every sip feels like a luxury, ColdKey(TM) metal straw for minimizing the amount of plastic sitting in your water, BevGuard(TM) technology to keep your drinks cold for 24+ hours, and a cup holder friendly base so you can enjoy your favorite beverages, free of leaks and spills throughout your daily journey. Made for stress-free sips. Era Flip Tumblers are 100% leakproof with cold beverages and carbonated beverages with ice when in the locked position. Not recommended to be used in the locked position with hot beverages. Features: Fully Covered Flip-Down Straw: SlideSeal(TM) magnetic lid flips and seals the straw for a hygienic drinking experience 100% Leakproof Lid: Leakproof when in locked position SoftSip(TM) Straw + ColdKey(TM) Technology: Silicone tip on the outside and metal straw on the inside to keep plastic out of your water and make every sip feel like a luxury Cup Holder Friendly: Fits most cup holders for easy transportation Easy To Clean: Every single piece is removable, making this the most hygienic tumbler there is