I am not familiar proper noun in earphone area, I would say
earphone ear mold:
earphone ear mold sleeve as a sleeve shape of custom-fit rubber mold.
earphone sleeve: good sound insulation effect, but would feel uncomfortable(or very uncomfortable after some time)
customize ear mold is expensive, and limit to some high-end phone. (A cheaper one may be apple's earphone, comfortable but can't isolate outer sound )
I just want to know if such thing exist, what is the name for such stuff?
PS:I think it would be good to customize sleeve mold to fit my ear. I mean the sleeve just looks like the picture 2. And it has a hole like normal ones, then I can plugin any other earphones I like, not limit to some special brand.