watchOS 5.0.1 (build 16R381) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-09-27T20:08:30Z. The update package is 971.1 MB. This is a delta (partial) update that requires 3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d94fcf18909f13b55400ba19077b66d7b0210e6a.zip.