iOS 13.3 (build 17C5053a) is an official Apple over-the-air update for the iPhone 6s, released on 2019-12-05T21:11:34Z. The update package is 64.65 MB. This is a delta (partial) update that requires 13.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: aac77b650a77074ad913644fe9bd8d30aca262cb.zip.