watchOS 4.0.1 (build 15R654) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2017-10-04T18:01:13Z. The update package is 42.87 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: 653790acc18273eb799d5ffa8b40c920f7741658.zip.