watchOS 4.1 (build 15R5846) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2017-10-20T17:04:15Z. The update package is 327.19 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: d1265a6ec878fd16e26b4b9705544501bd051a82.zip.