Oh geez, I thought the R wheels were 11 in the back and 10.5 in front! I corrected that in my post above sorry about that. Thanks for the correction.Wow that is actually a very reasonable price, to be honest! Looks great and now there is a new option for weight obsessives! I feel like the GT3RS and 2RS had magnesium wheels as options so it seems like a safe option with the modern manufacturing processes.
OP - if they were made in factory R sizes, then they are 11" F and 11.5" R.