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# automaticMaximumThickness

The maximum thickness of the split view item when it resizes due to automatic sizing.

```
var automaticMaximumThickness: CGFloat { get set }
```

## Discussion

Automatic sizing may happen when the split view item has a set [`preferredThicknessFraction`](/documentation/AppKit/NSSplitViewItem/preferredThicknessFraction) and the app enters full-screen mode, or when other split view items cause the item to change size. The user can still resize the item up to its absolute maximum size in [`maximumThickness`](/documentation/AppKit/NSSplitViewItem/maximumThickness) by dragging the divider.

The default value of this property is [`unspecifiedDimension`](/documentation/AppKit/NSSplitViewItem/unspecifiedDimension), which means the split view item doesn’t enforce an automatic maximum size.

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