Preferences
Set various aspects of TestFit and your project by using preferences.
![preferences](https://support.testfit.io/hs-fs/hubfs/CS%20-%20Customer%20Success/CS%20-%20Knowledge%20Base/CS%20-%20Knowledge%20Base/Getting%20started/preferences.jpg?width=476&height=879&name=preferences.jpg)
To get to preferences go to TestFit > Preferences in the Application Bar for Windows, or the Menu Bar for Mac.
NOTE: Units cannot be changed once any geometry has been drawn in the project.