All aluminum. Display base and shaft optional.
The ball is removable from the shaft, and it unscrews just like seen in the show. It's made from solid aluminum, with a static button top that is annodized blue. Unscrew it and give it to your favorite three-fingered child ;)
The display base is about 3" in diameter and made of solid aluminum like the other parts. It has a black coating, with the mudhorn clan of two crest engraved into the surface. The base is reversible, so you can flip it over if you prefer to display the knob with the crest hidden underneath. It stands about 5" tall.