I’ve been using these (along with a neoprene swim cap and 1mm jacket worn over a skinsuit) to extend my open water swimming season. I’m a female whose shoe size is 9 1/2, so I ordered size Small.My first thought when I saw how narrow the cuffs were was that I should have ordered Large—I thought, “No WAY will I get my feet past that!” But I tried anyway, because I know that while neoprene may seem impossibly tight, sometimes all you need is a little patience. So...The first couple of times I put the socks on, I had to turn them almost totally inside out, leaving a small pocket to stick my toes into, then gradually pull and work and pull and work the rest of the sock up the heel and ankle until it was all rightside-out and in the right position. After the first couple of wearings, they became much easier to put on. And then, to take them off, you just gently turn them inside-out, peeling them down and working them off your foot.Worth the effort—these socks keep my feet warm enough and stay on kick after kick. Very happy with them!