Sennheiser Replacement Cable for HD 25 Headphones
Also, my previous replacement cable (which I bought from Amazon) came with a hex key to undo the hinge, but this one doesn't (lucky I have a set of hex keys). I'm sure it's a fake, even though it has the Sennheiser labelling on the package.
Finally, and I hesitate to say this as it's such a subjective thing, but I'm pretty anal about my sound, and am sure it doesn't sound as good as the original, which is obvious from the moment you start listening.