From SmashWiki, the Super Smash Bros. wiki
The Custom Part is an item in both versions of Super Smash Bros. 4. Collecting one gives the player a custom special move, a Headgear or Outfit for Mii Fighters, or a piece of equipment. They can be obtained in several ways:
Retrieved from "https://www.ssbwiki.com/index.php?title=Custom_Part&oldid=915091"