# ClusterBoundary enum

Namespace: [Grasshopper2.Components.Standard](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.components.standard.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public enum ClusterBoundary
```

The various types of objects sitting on the boundary between a cluster and its inner document.

## Values

| Name | Value | Description |
| --- | --- | --- |
| None | 0 | No special cluster functionality is implied. |
| Input | 1 | A listen object acting as a cluster input. |
| Output | 2 | A shout object acting as a cluster output. |
| Index | 3 | A listen object acting a a looping cluster iteration counter. |