watchOS 4.1 (build 15R5835d) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2017-10-09T17:05:21Z. The update package is 110.03 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fb427610dfd87f79bd86cab78a8bb4bcc9a53801.zip.