Ive been reading Brainwavz Audio official website looking for this info but they dont mention it anywhere. The 11/12 actually fit her perfectly. If you listen to "chart" stuff, you will hear the compression and saturation that happens as they try to push stuff to the limit all the time. This was around three years or so ago I think and they had so much use due to their versatility. They were over 2" longer than what he needs. I have Adidas Cloudfoam shoes which I bought from Costco in size 7. My pinky toe is obviously almost poking through the side. Overall happy with the purchase ! In all fairness, I returned it assembled because I used it and threw out the boxes, which I disclosed. This radio?s reception was not good and all local stations were accompanied with plenty of static.