These are amazing.  I don't typically write reviews, that's how amazing these things are.  There is a little strip of grippy material on the heel so it doesn't slip off your foot.  I have other no show socks that are CONSTANTLY shifting and slipping.  These don't do that at all!  And they ride low enough that you can't see them creeping out the top of your shoe.  My shoe size is size 10 and these fit great.  I'll be purchasing more for sure.