watchOS 4.1 (build 15R5823c) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-09-27T16:59:15Z. The update package is 99.35 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: 03f645e4d6789e707581648fa31fab4f9e008140.zip.