This is the perfect little bag to carry your water bottle around a little more easily while you’re out and about on a hot day. I used a 4mm hook for a regular sized 32oz water bottle, and it was a perfectly snug fit. However, this pattern is easily adaptable. If you want a looser fit so that you can stash a snack or your license in it, upsize to a 5mm. If you have a more slender bottle, you can downsize the hook.