watchOS 6.1 (build 17S5076a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-10-16T17:13:57Z. The update package is 614.82 MB. This is a delta (partial) update that requires 6.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4378e9abdb049f4a8710d04ef1a4d3236850911c.zip.