100% LEAKPROOF, GUARANTEED: The Era series is the only 100% leakproof straw tumbler that works for both cold and carbonated beverages, thanks to our patent-pending Ü-Turn technology. So, you can toss your drink in your bag and take it on the go without ever spilling a drop. COLDKEY METAL STRAW: The Era series also has our ColdKey stainless steel straw so you can reduce the amount of plastic sitting in your water all day and experience a cool, crisp drinking experience with a soft-touch silicone tip on the outside to top it off. 24+ HOURS COLD: Thanks to our BevGuard insulation, the Era will keep your favorite drinks ice-cold for 24+ hours. CUP-HOLDER FRIENDLY BASE: The Era has a sleek, tapered design that fits all standard cup holders. LIFETIME WARRANTY: Backed by our lifetime guarantee, the Era will be your favorite drinking companion for the long haul.