Klean Kanteen Sports Cap

I use this cap with the KK bottle most of the time. The sports top is convenient when moving and when in vehicles that lack good cup holders. It attaches to the bottle neck via a plastic loop. If I want to drink from the mouth of the bottle instead, I just unscrew the cap and let it hang from the side so that I don't lose it.

I ordered the 18 oz. canteen first. Then I ordered the sports cap. I love it! The cap does not leak. I feel like I am doing something good for the environment when I drink from my "Kleen Kanteen." I will never buy bottled water again.

After ordering the Klean Kanteen 40oz I used it w/
its original top. Then I ordered the sports cap,
and what a difference. No leaking, easy to drink from,
convenient. I love it, and ordered one for each person
I am giving the Kanteen to. Get it!

Its a solid sports cap that is designed specifically for KK. The reason it whistles is that the Kanteen is solid steel and unlike plastic bottles you cannot squeeze it to get the water out. You actually have to suck on the cap to get the water out. There is actually a little soft plastic valve that opens when theres negative pressure in the bottle letting air in from the outside. This is what causes the whistling. If you orient the cap so that this valve is on top and not touching the water inside, it wont make that chirping noise. A bit annoying (thus the -1 star) but it isnt something that is a real dealbreaker.

We love that there is a sport top for our Klean Kanteens, but they are so noisy to drink out of! It sounds like a bird is whistling, if possible. My boys can't bring them to class because they disrupt the teacher. Other than that, they fit nicely and allow you a good flow.