You can tye a belly spinner with any jig head. Some lead head jigs are poured with the swivel attached.

To tye a belly a spinner you slide one end of the swivel loop (I bend the loop a little - making it oval) on the hook, up to the head. Lash it down with a couple of figure 8s then tye your pattern.

Roller swivels are best, crane are good, barrel aren't worth it - bind. Sizing is confusing.