watchOS 4.1 (build 15R5843a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2017-10-16T17:06:10Z. The update package is 147.21 MB. This is a delta (partial) update that requires 4.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6c1cb39d4a17c9180e4d88447c32f20008eb0ec5.zip.