I understand there might be some questions about the fit of these. According to one of our contacts at Head-fi, they won’t fit Shure, Westone, or Future Sonics without an additional monster tips adapter or using the core of the Shure Olive foam as an adapter. The nozzles also take T200 foams, if you want to get an idea of how small they can go.
I’m currently using them with Shozy Zero Earphones. After pulling at them a bit, I can get the ear tip to fit over the nozzle.