iOS 13.3 (build 17C5053a) is an official Apple over-the-air update for the iPhone 6s+, released on 2019-12-05T21:11:35Z. The update package is 336.58 MB. This is a delta (partial) update that requires 13.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 42870a65e333f16077375d5a741f6ce36436b6ed.zip.