IDK, but this seems really expensive for a clamp headphone hanger. If you do a search for "headphone clamp for desk" on Amazon, you get well over seven pages of some really nice ones for well under this price. I mean A LOT under this price. Sure most of them are single arm, but I'd say at least 25% of them are double. The only one that came close to $30 bucks was a really nice USB hub with double headphone arms. I personally don't think some taped on padding can justify the cost of this thing.
And for the record, I love this type of thing. I have many headphone hangers attached to my desk. Im not just being a hater. I just dont get why this costs so much.