watchOS 4.1 (build 15R5823c) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2017-09-27T17:00:01Z. The update package is 104.27 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 316d8412728600ae3428c73e8675a1a38b463645.zip.