iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone 7 (GSM), released on 2018-03-29T17:13:33Z. The update package is 733.96 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: bc410121faf6b29fa332f3cd88520354c9afe7d2.zip.