Era Flip 40oz is the world’s first 100% leakproof, covered, flip-down, straw tumbler. It has our fully leakproof SlideSeal™ lid that works for both cold and iced carbonated beverages, SoftSip™ silicone straw so every sip feels like a luxury, ColdKey™ metal straw for minimizing the amount of plastic sitting in your water, BevGuard™ 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 iced carbonated beverages when in the locked position. Not recommended to be used in the locked position with hot beverages. Using a 50% ice to liquid ratio is recommended when using carbonated beverages with your Era Flip.