This is a replacement lid for your 12 oz or 21 oz Hydro Flask. The Standard Mouth Loop Cap is a leak-proof, vented cap that allows hot vapors to escape while closing the lid, ensuring a smooth and easy seal. The Hydro Flask caps help to keep the flask's contents hot or cold.
There is a loop that allows you to clip your flask on to a backpack or messenger bag, making it easy to carry around.
Our patent-pending loop caps are made from polypropylene PP#5 and are BPA-free and 100% recyclable.