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# length

The extent of the box along its z-axis. Animatable.

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

## Discussion

The box is centered in its local coordinate system. For example, a box of length `10.0` extends from `-5.0` to `5.0` along the z-axis. The default width is `1.0`. A length of zero or less creates an empty geometry.

You can animate changes to this property’s value. See [Animating SceneKit Content](/documentation/SceneKit/animating-scenekit-content).

---

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