watchOS 4.1 (build 15R5823c) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-09-27T16:59:14Z. The update package is 559.66 MB. This is a delta (partial) update that requires 3.2.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a8a8784d036cbb25882c12475f2e9108d235a9b6.zip.