I’ll be ordering a 18k Gold ,2.4mm diamond nose stud with standard (20 gauge, 6.5 mm length) Would I beable to re-pierce my nostril with it?

we don't pierce with jewelry that people bring in. We use our own jewelry because we know what material it is made out of and we want to make sure that the jewelry has enough room for swelling

Ok cool. Do you know the gauge size and length of the jewelry is? So that when I order it it’d be the correct size?