watchOS 4.1 (build 15R5823c) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2017-09-27T16:59:34Z. The update package is 130.42 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: f415bbad2b3ebb00af92b4623713b683b9b209fa.zip.