I own these in a 13 but I wear a 12, so I bought the 12s. But the 12s fit like an 11 so they collect dust now and will probably be resold. Wilson has a QC issue with these. Otherwise they're great for relaxing the feet after pounding the courts. The footband is elastized for a snug fit. The 12s were far too tight and narrow. The 13s are still a little large but not uncomfortably so.