---
title: kAudioSession_OutputDestinationKey_ID
framework: audiotoolbox
role: symbol
role_heading: Global Variable
path: audiotoolbox/kaudiosession_outputdestinationkey_id
---

# kAudioSession_OutputDestinationKey_ID

The output destination.

## Declaration

```swift
let kAudioSession_OutputDestinationKey_ID: CFString!
```

## Discussion

Discussion A CFNumber object, defined by a USB audio accessory attached to the device through the iPad camera connection kit, that identifies the output destination. When setting an audio output destination on the accessory, use this identifier. For possible values, see Audio Output Routes.

## See Also

### Constants

- [kAudioSessionInputRoute_BluetoothHFP](audiotoolbox/kaudiosessioninputroute_bluetoothhfp.md)
- [kAudioSessionInputRoute_BuiltInMic](audiotoolbox/kaudiosessioninputroute_builtinmic.md)
- [kAudioSessionInputRoute_HeadsetMic](audiotoolbox/kaudiosessioninputroute_headsetmic.md)
- [kAudioSessionInputRoute_LineIn](audiotoolbox/kaudiosessioninputroute_linein.md)
- [kAudioSessionInputRoute_USBAudio](audiotoolbox/kaudiosessioninputroute_usbaudio.md)
- [kAudioSessionOutputRoute_AirPlay](audiotoolbox/kaudiosessionoutputroute_airplay.md)
- [kAudioSessionOutputRoute_BluetoothA2DP](audiotoolbox/kaudiosessionoutputroute_bluetootha2dp.md)
- [kAudioSessionOutputRoute_BluetoothHFP](audiotoolbox/kaudiosessionoutputroute_bluetoothhfp.md)
- [kAudioSessionOutputRoute_BuiltInReceiver](audiotoolbox/kaudiosessionoutputroute_builtinreceiver.md)
- [kAudioSessionOutputRoute_BuiltInSpeaker](audiotoolbox/kaudiosessionoutputroute_builtinspeaker.md)
- [kAudioSessionOutputRoute_HDMI](audiotoolbox/kaudiosessionoutputroute_hdmi.md)
- [kAudioSessionOutputRoute_Headphones](audiotoolbox/kaudiosessionoutputroute_headphones.md)
- [kAudioSessionOutputRoute_LineOut](audiotoolbox/kaudiosessionoutputroute_lineout.md)
- [kAudioSessionOutputRoute_USBAudio](audiotoolbox/kaudiosessionoutputroute_usbaudio.md)
- [kAudioSession_AudioRouteChangeKey_CurrentRouteDescription](audiotoolbox/kaudiosession_audioroutechangekey_currentroutedescription.md)