I used them with my Sennheiser HD660s. They work pretty fine but it is very difficult to attach them. The pins on them are slightly thicker than the original cable i guess. I am afraid to remove the cable to be honest, in case it breaks the headphone... Other than that, nice cables.
Product received was different than what I ordered. The picture uploaded below is what i actually received. It is still good and I am happy with it's performance but it is still an error in shipping. I ordered this specific design because of the added heat shrink around the connectors which I think will reduce the amount of wear at this problematic spot.