This interchangeable sports lid transforms your standard Hydro Flask water bottle into one with a pop-up top (sold separately) It fits all Hydro Flask standard size water bottles as well as Simple Modern Ascent Bottles, and a few others and is a game changer… especially if you drink water while biking, hiking or exercising. You can pop the top open with your teeth.
Per manufacturer, it’s BPA free and compatible with Hydro Flask Standard Mouth bottle 12 oz, 18 oz, 21 oz, 24 oz., Simple Modern Assent bottle, Classic Kleen Kanteen bottle, The Coldest Water bottle, and other standard bottles. Fits all standard size bottle's mouth about 1.81 inch.#LTKxPrime