watchOS 6.1 (build 17S5059e) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-10-02T17:11:18Z. The update package is 711.85 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: df2466269e060e506b51efc43b638a114d81f57d.zip.