“Size conversion makes this a most confusing process. I ordered the AU 5.5 which was indicated would be the true women's US size 8.5. Unfortunately, it was not and too small to be comfortable. I then ordered the AU 6 which equates to women's US 9. After comparing the feel and fit of each boot, I found the AU 6 (US 9) with the inserts included to be a great and very comfortable fit! I am also able to use my Good Feet Store arch supports and still be comfortable. I found the EU 39-40 size that I wear was much closer to indicating the AU size I needed than the US conversion was. I know this is confusing but I hope it helps. Highly recommend ordering 2 sizes if in doubt as the return process is quite simple!”