---
title: outputDeviceUniqueID
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avcaptureaudiopreviewoutput/outputdeviceuniqueid
---

# outputDeviceUniqueID

The unique identifier of the Core Audio output device to use for audio preview.

## Declaration

```swift
var outputDeviceUniqueID: String? { get set }
```

## Discussion

Discussion Set the value to the unique identifier of the audio output device, or nil to use default system output.

## See Also

### Configuring the output

- [volume](avfoundation/avcaptureaudiopreviewoutput/volume.md)