Ever tried to chug water from a metal bottle with a sport cap? You know, a bottle you can’t squeeze? Annoying. Hard work. And definitely not thirst quenching. That's why we spent almost two years developing the new Sport Cap 2.0 — a sport cap for stainless steel Klean Kanteen™ Classics that delivers some serious flow. Plus the cap has a handy loop that makes it easy to clip your bottle onto a backpack, climbing harness or a work belt. And of course it's made from BPA- and toxin-free polypropylene #5.