A small alicorn or a unicorn horn great size for BJD dolls. A large size best for SD dolls, but work for MSD as well.
Item is just the 3D print, you will need a 7mm in diameter disc magnet to super glue in. If magnet is a little big use a dremel or knife to widen the inside hole to fit the magnet in.
Let us know if you would like a different styel or size!