The Loop Cap was designed with athletes and multitaskers in mind. The handy attachment loop makes it easy to clip your Klean Kanteen onto your backpack, climbing harness, messenger bag or any other place you need quick, easy access to your drink.
Made from polypropylene (pp#5)
No BPA, phthalates, lead or other toxins
Interchangeable with all Kanteen Classic bottle sizes
If you want leak proof, loop cap is the way to go. Since it is hollow, I have seen people use it as a cup for their children when drinking water on the go. Personally I prefer to drink from the bottle than a sports cap ( as it messes up my lipstick)