Download iOS 12.3.1 Build 16F203 IPSW Firmware Restore Files
Download the IPSW iOS 12.3.1 (Build 16F203) firmware file released at 24 May 2019 intended to restore iPhone 5s (GSM) via iTunes. IPSW iOS 12.3.1 build 16F203 is unsigned by Apple to update Apple device software.