watchOS 4.1 (build 15R5843a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-10-16T17:05:45Z. The update package is 241.92 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: 42c7b81866bf0edc31c375c115b6624fd27b253e.zip.