I found the 24 oz Polar bottle fit pretty well, even if it did deform just perceptibly. The Iris cage did mar the Polar with its imprint, though it mostly washed off, not a huge deal.

The Polar kept cold water cool over my 10 mile commute, while the 20 oz CamelBak Brook kept cold water cold. I carried the Brook in the net on the side of my backpack.

I'm guessing the Polar might be the best option for Iris cages unless there's a bottle closer to 23 cm, like the 27 oz Klean Kanteen.








One thing to be careful of, the handle around the top of the Polar bottle can hook your downtube shifter if not careful.