Compatible Lid：Fits wide mouth sport water bottle, theoretically including Hydro Flask, FIFTY/FIFTY, SimpleModern, Takeya, MIRA, etc. Perfectly fits Hydro Flask 12oz, 18oz, 32oz, 40oz and 64oz wide mouth bottles. Mouth diameter 2.28 inches. Improved Design：New improved flip lid with button. Press the button, the flip lid will sprang open automatically. One-hand operation makes drinking easier. Material：Made of high quality materials. All are BPA and Toxin-free, safe for kids and adults. High Quality：New sealed rubber can provide better sealing, dramatically reduce water leaking issue. Better Choice：The lid is a good choice for your water bottle, if you have any question, let us know. After-sales Service Team will help you deal with it.