# Editor.EditorUtility.Prefabs.IsOuterMostPrefabRoot

```csharp
static bool IsOuterMostPrefabRoot(object obj)
```

Returns the name of the prefab file that this GameObject or Component is an instance of.

### Parameters

- `obj` (`object`)

### Returns

`bool`

Declared in [Editor.EditorUtility.Prefabs](/api/Editor.EditorUtility.Prefabs).
Assembly: `Sandbox.Tools`.