# Customizing an existing annotation tool in our viewer toolbar

It’s possible to customize the following properties of built-in items:

- `IsDisabled`

- `Icon`

- `Tooltip`

- `StyleClass`

Refer to the [API reference](https://www.nutrient.io/api/maui/) to learn more about each individual property.
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## Related pages

- [Rearranging annotation tools in our viewer toolbar](/guides/maui/user-interface/annotation-toolbar/rearrange.md)
- [Removing an annotation tool from our viewer toolbar](/guides/maui/user-interface/annotation-toolbar/remove-a-tool.md)
- [Create custom annotation tools in MAUI PDF viewer](/guides/maui/user-interface/annotation-toolbar/create-a-new-tool.md)