My girls have metal allergies and can't wear anything but 24 gold and thankfully, plastic.  These are cute little rhinestone looking studs that are easy to put in and take out so we can do frequent changes if they please.  They are pretty colors and so far my 4 year old and 5 year old have not lost or broken a single one. They don't hurt their ears or behind their ears when they sleep on them and they are perfect dainty size for little girls.  I would highly recommend.