I tend to be hard on headphone cables, so after I broke my HD600 cables, I bought these, since they fit both HD600 and HD650's, and I have no need for a 3,5mm jack on my HD600's cables.
I could detect no change in sound compared to stock HD600 cables.
They seem somewhat sturdier than stock HD600 cables, and they have held up to my abuse for a couple of years now without issues.
So great cable for the HD600 at a very good price.