watchOS 5.0.1 (build 16R381) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-09-27T20:08:40Z. The update package is 768.4 MB. This is a delta (partial) update that requires 4.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c47fca26b7906de4da67423ef711625fb2346278.zip.