These black Nike crew socks have a grey band inside the cuff. Why is this detail important?  Having purchased & laundered possibly hundreds of black Nike crew socks for my son over the years I can attest to the fact that these - the ones WITH the grey band inside the cuff - are more cushioned, more tightly woven, durable, and comfortable than Nike socks without the grey band inside the cuff. When I inadvertently purchase a package without the gray band inside the cuff it is apparent after a few weeks: the banded socks are more colorfast and retain their cushion, thickness, and elasticity white those without the band are crushed flat at the ball of the foot and heel, misshapen and faded (i.e. destined for the garage rag bag).
These are fitted anatomically evidenced by the R on the right sock & L on the left. I have only recently begun to appreciate the difference, but the comfort of a anatomically fitted sock is clear - there is no excess fabric on the outside (by the little toe).
I have only been able to find these at Amazon in the past few months. JCP & other local department stores only sell the kind without the grey band.