Sennheiser HD540 Reference, Reference II, Reference Gold EarPad Adapter.

This is a basic 100m Ring for HD540 Headphones. This will NOT work for the HD530 series and I'm not sure about the HD560 Ovation.

You can use any Earpads, I have used HM5 Hybrids. I suggest to not buy the original HD540 pads as the foam will hardly survive 3 years.