My Ei.3 are universal these days. I think the shells have some similarities with Shure and Westone, but they certainly feel more solid and isolate better than my SE215, which were the ones I used previously. Although I believe Piotr uses a 3D printer for the shells, they will take a while to make because the design is still custom. Anyway, that's not really advice, just an excuse to show them off a bit.
dang those look good. I like how it has a 2 pin too. too bad rn it's out the budget and the shipping might take longer than needed but I would love to snag a 2 pin since after a month the se215 mmcx would always cut out on me