Wicked cushions had some good replacement parts for xm4s. I bought a couple replacements from them. They had really good customer service when I had a bad clip on one or the earpads too.

I paid 30$CAD 2 years ago for mine. The Sony OEM ones are very comfortable but they compress quickly imo. My ears are a little angled so they are always pinching when the OEM pads compressed too much. The wicked cushions ones I got are a bit taller to start off with and haven’t had a single problem with them compressing so far. Only bought the second set of pads because I wanted a different colour.

I will buy more from them when I get a new headset. Stupid hinges on xm4s