watchOS 5.0.1 (build 16R381) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-09-27T20:08:33Z. The update package is 738.78 MB. This is a delta (partial) update that requires 4.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 15d0a4ca73494f5d7f9f5399d23a70a4939bab09.zip.