watchOS 4.1 (build 15R5846) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2017-10-20T17:04:19Z. The update package is 83.63 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: 161fd21af2116028cd3dade692de0050c451c599.zip.