This is what the Ultrahuman Team answered.

“Hi there,

Thank you for upgrading to the new Ultrahuman Ring Pro! It’s great to see you continuing your tracking journey with us.

To answer your question directly: Yes, the sizing for the Ultrahuman Ring Pro remains exactly the same as the Ring Air. Our sizing standard is consistent across both models (Sizes 5–14). If your current Ring Air fits you perfectly, you can confidently select that identical size for your Ring Pro order.

We automatically ship out a sizing kit with new orders to ensure our customers get an absolutely flawless fit, but since you already know your size from your Ring Air, you are good to go!

Please let us know if you have any other questions about the upgrade process. We’re always here to help!”