I was looking for exchange pads for my Harmonicdyne Poseidon Headphones and I'm happy to report that the brainwavz XL Pads are a perfect fit!
Since they're suited for the Poseidon - Owners of the similar shaped Harmonicdyne Zeus Headphones will be equally happy with these Pads.
The soft material is very pleasing and to my surprise it seems even a bit better in terms of noise cancelation than the stock micro suede pads on the Poseidon while still maintaining the Open character you want on this kind of Headphones.