---
title: isFollowingExternalSyncDevice
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avcapturedevice/isfollowingexternalsyncdevice
---

# isFollowingExternalSyncDevice

Whether the device is following an external sync device.

## Declaration

```swift
var isFollowingExternalSyncDevice: Bool { get }
```

## Discussion

Discussion See follow(_:videoFrameDuration:delegate:) for more information on external sync.

## See Also

### Synchronizing with external devices

- [minSupportedExternalSyncFrameDuration](avfoundation/avcapturedevice/minsupportedexternalsyncframeduration.md)
- [isVideoFrameDurationLocked](avfoundation/avcapturedevice/isvideoframedurationlocked.md)
- [minSupportedLockedVideoFrameDuration](avfoundation/avcapturedevice/minsupportedlockedvideoframeduration.md)