I don't know if this fits on Galaxy stuff. I put them on my Grados. In any case, the things seal off enormously! In public transport etc., brilliant - on foot on the street - absolutely too tight!
I don't like the Galaxy Buds 2 in general, but this isolation is pretty good if that's your need. You are just totally isolated or almost totally. Only really loud noises get through, e.g. when a train passes right by you.