I ordered the larger size as I thought that was meant for the actually jewelry piece, not the post. It appears the 8mm is for the post. The post is a bit challenging to get through the earring hole, but managed to do so. However, the backing must be universal, as it's a bit challenging to attach once through.

My wife loved the earrings for an anniversary present! The box was a nice touch as well. I would highly recommend them for your needs and gifts!

LOVE 💕 the double-up posts. They look and feel effortless and go great with double and triple dot studs. I always get compliments on them.