Available with 3D Analyst license.
The Style Manager dialog box allows you to organize styles and their contents. You can cut, copy, paste, rename, and modify any style contents. You can also create new styles and symbols. You can create a new style and copy your personal style contents, as well as symbols from other existing styles, or you can import 3D models into styles.
You can easily distinguish which folders contain elements and symbols, which can be modified, and which are empty.
The Style Manager is accessed from the Customize menu in ArcScene, ArcGlobe, and ArcMap.