One point which seems to get overlooked in many reviews, is the fact this headset charges via USB-C. Uodated from yesterday. Not too sure what the bottoms are made of but they are more cushiony than the others. I put a spacer under it and it works fine. Every item in the box including the rubber and plastic pieces felt very well made and solid. Happened to me - wont assemble. I needed to email in scans of the plate on the back with all the tech details before they accepted that it was indeed a Logitech product. Seems like the shoe is made of some type of rubber, but not sure. It was a bit of a challenge to install it. I’d like to get my money back so I can buy some real Birkenstock’s.