Please participate in our “Let it Snow” Xmas 2020 Group youtube project!”
If you're talking about his Pelican Reel video, it looks like he may have a Bonmusica shoulder rest on his fiddle. Fiddlerman here sells them, look for them under accessories/shoulder rests and see if you think that's what it is.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. ~Herm Albright