I have been trying to source the parts for a few months now but still can't.[br]
You can read about my frustrations on [link|https://community.sony.co.uk/t5/portable-audio/wh-1000xm3-headphones-both-headband-sliders-broke/td-p/3819565|the Sony forum|new_window=true]. I also tried the eBay[br]
parts but they don't fit exactly because they're slightly shorter./
If anyone reading this has managed to source parts from somewhere, please do share the link.