Not sure if this is a mistake so *please* check with Amazon before purchase.
Why do I think that? Well, this product comes under the "Save £10 off £50 on Clothing & Shoes for your Child" promotion, strangely... pretty sure, judging by (good) reviews, that's its adult size.
Could try to use that promotion with kids stuff if you want, not 100% certain it'll work though, caveal emptor!
Edit: My order just arrived! Perfect fit for male adult size 11 :-)
Sizes available (adult): 6-11 (including half sizes).