In the military we have strict guidelines for earrings for women, they have to be between 4-6mm in size and for cerain ranks they are gold and for others silver.  These fit the bill perfectly for me!  The backings included are sturdy and they're rounded along the end that pokes out, it actually makes it possible for me to sleep in them without having the ends stab me behind the ear if I roll over.  I love these!  I can wear them, and then forget that I even have them in!