Question about Ultrahuman Ring AIR size 11

Il y a un set pour tester la taille :)
Ultrahuman Ring Air Sizing Kit Grösse 5-14 Colored

You can buy test rings. You can wear these. It's best to wear them for a few days so that you know which finger to use. I used the index finger. (would be a different size than the ring finger).

Do you send a box of test rings to determine the ring size?