watchOS 6.1 (build 17S5054e) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-09-23T17:05:00Z. The update package is 272.4 MB. This is a delta (partial) update that requires 6.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 86ab6fea029054164ec32d598d5a74f0c931b3b9.zip.