watchOS 4.1 (build 15R5835d) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-10-09T17:04:39Z. The update package is 112.49 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: 942fd73f8454e09c2609555bc7f16997a417dce6.zip.